Gardening Terms

Accent PlantThis could be a focal point plant. A plant to catch attention. Could also be called an anchor plant.
AcheveA one seeded fruit which does not split open to release it's seed, ie. the "seeds" on a strawberry.
Acid RainRainwater that contains sulfur dioxide and other pollutants from industrial plants. There has been considerable damage done to the forests of the US and Canada.
Acid SoilSoil that is lower than 7.0 ph (higher would be alkaline). Acidity is measured by the amount of calcium in the soil, as is alkaline soil.
AdventitiousHaving growth from places where normally growth does not occur (i.e. if a stem is buried and a plant will grow.)
Adventitious PlantA young plant that develops in an asexual manner on the leaves or stems of the mother plant. (Kolanchoe are good examples of this.)
AerationThe loosening of soil by digging or other mechanical means to allow air to pass freely, usually done on lawns.
Aerial RootA root which grows out from the stem above ground level. Aerial roots are commonly seen on mature specimens of Monstera deliciosa.
AerobicUsually used for describing a characteristic of compost heaps. Describes organisms living or occurring only in the presence of oxygen.
Aggregate CultureThe use of solid material to grow plants. Some examples are: gravel, rockwool, sand, all with the additional use of a nutrient water soluble solution.
Agricultural Extension ServiceA county agency that is supported and monitored by the land grant university for each individual state. Great place to seek out the horticultural agent, receive publications, and advice. This is your taxes in action.
Air LayeringA method of propagating single-stem plants, such as Ficus elastica decora, which have lost their lower leaves and become leggy. An incision is made to a portion of outer stem layer, damp sphagnum moss is wrapped in a bag around it until roots develop. Then it is cut and replanted with its shorter stem size.
Alkaline SoilSoil that has a pH level of about 7.0 or more. Sometimes referred to as "sweet" soil.
All America Selections (Aas)This is a group of people in the horticultural business who test new cultivars of flowers and vegetables. All of these gold medal winners can be raised from seed.
All American Rose Selections, Inc (Arrs)This is made up of roses that have been on trial for two years in official test gardens throughout the US. The association is comprised of rose producers, growers, and people who introduce new hybrids.
AlleeA very formal design of planting trees lining both sides of a path or drive.
AllelopathyThe release of chemicals by certain plants that will prevent the growing of other plants nearby. Walnut trees are very well known to do this.
AlpinePlants from high mountain regions. Anything that is from above the tree line. They are able to overwinter beneath deep snow protected from extreme low temperature by their moisture.
Alpine HouseA special greenhouse created to meet the requirements of alpines. It is usually kept cool in the summer by shading the glass. In the winter it is unheated unless it needs to provide protection from very severe cold.
AmendmentUsually referring to some form of organic material being added to the soil for the purpose of improvement.
AmphibiousThe ability of plants to brow both in aquatic and in the exposed soil. Usually in a moist or boggy condition, when the winter recedes in the area.
AnaerobicDescribes organisms living or occurring when oxygen is absent. Usually term used when talking about compost heaps.
AnnualA plant that will complete its life cycle in one growing season.
AphidsSmall sap sucking insects. They infect foliage and are easily recognized by the sugary "honey dew" that they secrete that often attracts ants. Can be controlled by application of soapy solution. (see Sooty Mold)
AquaticPlant which grows partially or completely in water.
ArborA free standing structure used in the garden to support vines or climbing plants of all sorts for shade, a walkway, or just a focal point. This term is sometimes used interchangeably with pergola.
ArboretumThis is a garden with a large collection of trees and shrubs. They are specifically grown for scientific or educational purpose.
ArboristA specialist who cares and maintains trees. Everything from planting, to pruning and also diagnosing and treating diseases.
AsexualThis is a means of propagation that does not include seed production. Therefore propagating by cuttage, dividing and layering.
AtriumA structure that provides lots of above light for plants. Commercial buildings often have their foyer as an atrium. Many homes have built in atriums.
AuxinA hormone that controls plant growth.
B And BBalled and burlap, a method in which plants are sold where the roots of a plant have been lifted and wrapped in burlap (sometimes plastic covered material) to keep it together until transplanted. Large trees are often sold this way.
Backbulbrefers to the propagation of an orchid. It is the old, dormant pseudobulb, it may be leafless, but will still produce a new plant.
BackfillReplacing dirt from the original hole after planting.
Backyard Wildlife HabitatA dreamy situation where native plant materials are providing food and shelter for protection and reproduction for birds, insects, and mammals in ones own backyard.
BaleThe area of the trunk between the base of a tree and the lowest branch.
Bare RootPlants that have been dug out of the ground when dormant. The soil is shaken free, washed and stored until shipment. Roses and daylilies commonly come this way, as well as smaller shrubs and bushes, sold in their dormancy.
Bedding PlantUsually an annual plant temporarily in a garden display. Some interstates have "smiley faces" that are done in a bedding plant display. Sometimes called carpet bedding.
Bell JarAn old term and glass container which is bell shaped. On the top is a knob for the use of protection of a delicate plant. From the Victorian Era and now days known as a cloche.
Beneficial InsectThese are insects that will improve and work in our gardens. By improving the soil, going after harmful insects, and will pollinate plants. Ladybeetles, earthworms, and bees  are well known.
BermA landscaping technique that is used to create interest, privacy, or screening. It may also divert water runoff. It is made by creating a mound of earth or a hill.
BicolourA flower with petals which bear two distinctly different colors.
BiennialA plant that will require two growing seasons to complete its life cycle. In the first year leaves. In the second year has blooms and seeds (i.e. foxglove, hollyhock, rose campion.)
BigenericA hybrid that is created by crossing two different genera.
Binomial NomenclatureThe current scientific method of naming species of plants and animals.
Biological Pest ControlUsing living organisms such as beneficial insects or parasites to destroy garden pests (i.e.. BT beneficial nematodes.)
Black SpotA disease on the foliage of roses. It is caused by moisture. To avoid, plant disease resistant roses. Clean up after pruning. One can use fungicide during damp weather captan, copper, or lime sulfur are most effective when you follow the instructions carefully. One can also use baking soda (sodium bicarbonate) at a rate of one teaspoon to one gallon. Use in the morning to prevent sun scald. One can also try neem oil.
BlanchTo keep light from the leaves and stems, keeping the pant tissue soft (i.e. endive is grown this way).
BloomA natural mealy or waxy coating covering the leaves of some house plants.
Blossom End RotA cultural deficiency created by a lack of calcium. Very closely related to extreme temperatures, uneven watering, and root damage. Most commonly seen in peppers and tomatoes.
Bog PlantPlants that preferred damp and most sail as their habitat (i.e. pitcher plant, Venus fly trap.)
BoleThe area of a tree trunk that is from the ground to the first major branch.
BoltAnnual vegetables or flowers that grow quickly to flowering stage, at the expense of their best overall development, and go to seed (i.e. dill in hot weather).
BonemealA fertilizer made from crushed animal bones. It is a natural high phosphorus fertilizer, very slow releasing and good for root development.
Bones-Of-The-GardenIn the language of garden design this is the permanent structural elements that give the shape to gardens: paths, walls, steps, fences, trellises, seats, water gardens, and hedges.
BonsaiThe art of miniaturizing trees by careful root and stem pruning and root restriction.
Botanical NameThe Latin scientific name of a plant is its botanical name. There is only one botanical name per plant so if you want a specific variety, use it's botanical name to be sure you are getting what you want. Common names tend to be confusing.
Bottle GardenA small terrarium created in a bottle. A miniature eco-system.
Bottom HeatAn arrangement used in propagation. Usually electric heating cables will run through the base of the propagation medium. Great for seed germination and cuttings.
BractA modified leaf, sometimes colored and sometimes mistaken for a petal. Examples of house plants with showy bracts are Poinsettia, Aphelandra, and Bougainvillea.
BroadcastA method by which seeds or fertilizer are scattering randomly to cover an area.
Brown RotA fungus that is very common disease on fruit. Buy disease resistant varieties. Remove all infected parts of the plant.
BtBacillus thuringiensis. A bacterium which will destroy the stomach cells of insects that consume it. It degrades quickly in sunlight so spray early in the evening. This biological insecticides will also kill young butterfly caterpillars. 
BudThe embryonic shoot on a stem, branch, or tuber. It is the beginning of a bloom.
BulbA storage organ, usually formed below ground level, used for propagation. A true bulb consists of fleshy scales surrounding the central bud. We often think of spring and fall bulbs.
BulbilAn immature small bulb formed on the stem of a plant: e.g. Lily.
BushA many branched small shrub with no distinct main stems.
Calcitic LimestoneA common material used for "liming" soil that has an acid level that is too high. this type is most commonly used and contains calcium carbonate.
CallusScar tissue that forms when a plant has been damaged or cut. When propagating some succulents it is best to have the leaf form a callus, to prevent disease and rotting.
CambiumThis is the thin membrane that grows just under the bark of a plant.
CaneA slender, straight, not very woody branch or stem of a plant (i.e. bamboo, rose, raspberry and blackberry bushes.)
CankerAn area on soft or rotten woody stems or twigs that is caused by bacteria and fungi.
CanopyThe crowns of trees forming the top layer in the woods or forest. Considered the high shade of gardens.
CapsuleA dry seed pod that will split wide open when mature..
CatkinUsually petal-less flowers arranged in a spike.
Cell PackA group of gardeners traveling together in a confined space for snipping and stealing plant material in a botanical garden.
ChlorophyllThe green pigment in leaves. It will be dominant in the plant when present or healthy.
Clay AggerateA product that is manufactured exclusively in high tech kilns in Germany and used as a soil replacement on hydroponics. It once was very popular in the late '70's & '80's. Now making a comeback.
ClimbersThose gardeners who are willing to hike for distances to see an alpine specimen. 
ClocheThis is a cover for protecting plants from the cold. In the early 19th century it was more popular, being bell shaped. Now, more conventional models are in all the catalogs.
CloneA genetically identical group of plants, created from one individual by vegetative propagation.
Club RootA disease of cabbages and some related vegetables caused by the slime mold fungus.
Cold CompostA method by which organic material just rots on its own. It may take months or years to naturally decompose. There may be a significant amount of weed seeds. And, there may be the danger of some disease organisms still in the compost.
Cole CropsThese are members of the cabbage family (ie. broccoli, cabbage, cauliflower, kale, collards, kohlorabi)
Common NameThe name by which plants are known by non-botanists. Plants that have a short history of cultivation may not have a common name. these names vary from country to country, even from region to region.
CompactionOften this term comes up when one is talking about new landscaping around a new construction whether it be a private home site, or commercial site. Compaction is created by heavy machinery squeezing the layers of the soil together. It is destructive to the composition and structure of the soil. No longer are there healthy air pockets for roots. The soil is no longer of good texture for planting. Often nutrients are washed away due to poor drainage, or no drainage at all.
Companion PlantingDifferent plants that are planted together for the benefit of each other. Whether it be color or roots deeper to bring up the nutrients for the secondary plant. Ground covers are great companion plants.
Complete Fertilizer A fertilizer that can provide all the three main elements: nitrogen, phosphorus, and potassium.
CompostUsual meaning for the house plant grower is a potting or seed/cutting mixture made from peat ("soil less compost") or sterilized soil ("loam compost") plus other materials such as sand, lime, and fertilizer. Compost is also a term for decomposed organic matter such as what is left after a compost heap has degraded vegetable and animal matter. An excellent source of organic material for rebuilding and enriching soil.
ConiferAn evergreen, generally green, sometimes cone shaped. Generally in a northern region.
ConservatoryA building build partially or entirely of glass attached to the house and where a large number of plants are grown. Not to be confused with a greenhouse.
CordonA very interesting way to grow fruit trees. Apples and pears do well in this mode. The tree is repeatedly pruned and trained to grow as a single rope like stem. For lack of space, this is ideal.
CormThis is a swollen, underground stem base used for propagation: e.g. Crocus.
CotyledonThe first set of leaves to grow after a seed has germinated.
Cover CropA crop that is planted to add humus to the soil or to control weeds (i.e.. winter rye). Usually done between normal planting seasons.
Creeperany plant that will make long shoots and grow along the ground such as creeping fig, ivy, or Virginia creeper.
CrockingAny material used in the bottom of containers to provide drainage (i.e. shells, rocks, broken pottery, Styrofoam.)
CrossAnother name for hybrid, but used in much more common terms.
Cross PollinationThe transfer of pollen from the flower of one plant to the flower on a different plant. Many species require this to set seed. As opposed to self-pollination. 
CrownThe region where shoot and root join, usually at or very near the ground level.
CruciferAny plant in the crucifer of mustard family. Those flowers with four petals are arranged like a cross.
Culinary HerbA plant grown for its strong flavor which is used to cook with in dishes and salads. the parts of the plant used are the leaves, flowers, or bulbs.
CultivarUsed when determining plant names. Indicates the variety originated in cultivation and not the wild. This portion of a plants name is usually not Latin.
CultivateBreaking the topsoil so water and air can penetrate, and, to prevent weeds.
CultivationThe technique of weeding and hoeing for the purpose of increasing the air in the to layers of the soil and to break up the soil so water will penetrate.
CulunIn the bamboo world this refers to the stem of grasses being usually hollow.
Cut BackTrimming or cutting moderately, making sure some of the last season's growth is left, to clean the plant up and the encourage new growth.
CuttingThis can be a leaf, roots, shoot, stem, or a bud that has been cut off and then used in propagation.
CycadAn ancient group of plants that were very abundant in the "age of dinosaurs" (the Jurasic and Cretaceous periods). There are less than 200 species that survive today and are growing in the warmer regions of the world. Often thought of as long-lived flowerless plants. Most are palm or fern-like. 
Damping OffThis is a decayed young seedling at ground level, caused by a fungal attack. The result of soil borne diseases and over watering.
Dappled ShadeHigh shade that is created by allowing sun to shine through.
Dark-Dependent SeedsSeeds that germinate only in darkness. So, must be covered with soil.
Day LengthThis merely is the number of hours from sunrise to sunset. Sometimes used interchangeably with photo period.
Day NeutralA plant whose blooming period is not affected by the length of day.
DeadheadingPinch here, snip there, removing spent flowers that have already bloomed. This is done for the benefit of the plant to prevent disease, prevent seed development and will encourage more vigorous blooming and a bushier plant.
DeciduousThese are plants that loose their leaves at the end of the growing season. Maple trees are a good example.
DethatchThe process of taking up dead grass and plant material that builds up under the grass making the soil easier to absorb nutrients.
DibbleA tool used to make holes for seeds or bulbs: a pencil end, dowel, or anything that works for the situation.
DiebackA process caused by disease or pests. It is the death of the tips of branches and shoots. It will progress until the whole plant dies.
DioceciousA plant which bears either male of female flowers. (Compare to Monoecious)
Direct Seedingputting the seed directly in the soil as opposed to transplanting seedlings.
DisbuddingIn reference to fruit crops, by selectively taking off buds to diminish the crop production and to have quality over quantity.
Dish GardenThis arrangement is most seen in florists. Many plants grown together to be used indoors for a focal point of greenery. (see European Dish Garden article)
Distilled WaterPure water free from dissolved salts. Formerly made by distillation, now produced chemically by demineralization.
DitherJust a plain old utensil of any kind to make a hole in the ground to drop a seed into.
DivisionA method of propagating plants by separating each one into two or more sections and then repotting (i.e. perennials are easily propagated this way.)
Dormant OilA great horticultural oil to be used on fruit trees or any plant material that has insects. It mainly kills the eggs that are not seen. Read the directions carefully not to be used in high temperatures. There are several brands on the market.
Dormant Period (Dormancy)This is the time when a plant has naturally stopped growing and the leaves have fallen or the top growth has died down. The dormant period is usually, but not always, in winter. Most plants need it to perform.
Double DiggingA method of deep cultivation.
Double FlowerA flower that is full from overlapping petals.
Double PottingPlacing a potted plant in a larger pot with damp peat moss surrounding it. The peat is kept moist and provides a humid evaporative effect for the potted plant nestled between it. Used a lot to dress up a working clay pot.
Downy MildewA certain kind of mildew caused by a special fungi. Often confused with sooty mildew and powdery mildew. As with all mildews it is a problem in hot and humid weather. And, like many fungi it transports its spores. The plants affected will have fuzzy patches on the leaves.
DrainageHow water moves through the soil. A real important factor for most plants and gardens.  In general water should move through the soil whether in a garden or in a container somewhat easily. If there is standing water create better drainage by adding non-porous material.
DrawnReferring to the structure of a plant, one that is too tall and has grown too weak. Caused by growing in too little light or too close together. Often is the case in flats in nurseries. Buyer beware.
DriftA design term generally attributed to Gertrude Jekyll. To express a feeling in with plants. The technique is to plant flowers thicker in the center and further apart on the outskirts.
Drip IrrigationA trickle irrigation system. Highly recommended for soaking the soil well.
Drip LineThe imaginary line under the tips of the canopy of a tree.
DrupeA type of fruit (i.e. plums, cherries, olives, peaches). Also considered stone fruits. The fruit wall is fleshy. The outside layer is generally juicy. The one seed fruit will not open up. 
DwarfShorter than its normal growth. Each family of plants has a height recommendation for dwarfness.
Edging PlantOn the edge or border of a bed.
EfflorescenceThe deposit of calcium and fertilizer salts on the outer surfaces of clay pots.
EndemicPlants which are of a certain geographic area and generally are confined to that place.
EpiphyteThis is a plant which grows above ground attaching itself to trees or rocks. A good example is the Amazon Air Plant or Spanish Moss.
ErosionThe wearing away of soil created by man, rain, or wind. Not a healthy situation.
EscapeA plant that is on its way to becoming naturalized in an area. Just exactly as it reads, it has escaped from cultivation.
EspalierThe method of training a tree or shrub as to grow in a pattern. Often pear trees, apple trees, or ornamentals.
EvapotranspirationKnown as ET, it is the amount of water that transpires through a plants leaves combined with the amount that evaporates from the soil in which it is growing.
EverbloomingThose flowers that will bloom all season.
EvergreenA plant that will bear foliage throughout the year.
EverlastingFlowers that have been grown for drying and preserving.
ExoticPlants that are native to other parts of the world and have been introduced here. Watch out. honeysuckle and purple loosestrife are invasive exotic pests.
EyeTwo unrelated meanings: an undeveloped growth bud (as in a potato) or the center of a flower (as in a daylily).
F1Breeders use this term and it refers to the first generation offspring, from two plants that have been bred. The F1 may have desired qualities of either or both parents.
F2This is the product of two F1 plants that have been crossed. This is considered the second generation. This will not necessarily produce a great plant.
Fairy RingA circle of fungal growth.
FamilyOne genus or several genera which have a basically similar floral pattern make up a family (i.e. LILLACEAE (lily), IRIDACEAE (iris), ROSACEAE (rose), ORCHIDACEAE (orchid))
FasciationThis effects many herbaceous and woody plants. This is a genetic mutation or imbalance in growth caused by absorption of a herbicide. Remove all effected stems.
FertilizeThe act of or the actual substance added to soil to provide additional nutrients for plants. May also be used to describe the pollination process flowers undergo with the help of bees and other insects. There are organic and chemical fertilizers.
Field GrownGrown in the field, as opposed to root cuttings which are grown in pots in greenhouses.
FlatA shallow wooden box or plastic tray used to start cuttings or seedlings. Annuals may be purchased in a flat.
Flore PlenoA botanical term describing a flower with extra petals.
Foiliar FertilizerA liquid, water soluble, fertilizer applied to a plant's foliage in a fine spray so that the plant can absorb the nutrients through its leaves.
ForcingThe process of making a plant grow or flower before its natural season. Usually done indoors (i.e. paperwhites).
Foundation PlantingAny plant that is used around a building for the sole purpose of making it look more esthetic. In earlier days it was to cover the foundation.
FrondA leaf of a fern or palm. The limbs of a palm tree.
FrostThe freezing and condensation of moisture in the air. Frost dates are important to know for your zone or area.
Frost HardyPlants that are able to survive winter frosts without damage to their leaves (i.e. evergreens) or damage to dormant stems, buts or roots (i.e. deciduous plants). Very much relative to geographic areas.
Frost TenderThese plants will be damaged or killed by even the lightest of winter frosts. Most evident would be tropical plants stretched to a cooler zone.
Fruit FlyA small insect pest that will lay its eggs beneath the surface of developing fruits. The larvae will then grow quickly and exit through holes in the fruit or vegetable causing rot.
Full ShadeThis shade is sometimes called deep shade and is created by mature trees.
Full SunSix hours or more in the direct sun during the growing season of the year.
FungicideA chemical used to control diseases caused by fungi.
FungusA primitive form of plant life. It is not vascular, and non-photo synthetic organism powdery mildew, sooty mold, mushrooms.
FurrowA depression in the planting garden either dug by a spade or a plow. It is created to be planted in or to be drainage.
FusariumThis fungal disease is soil borne and causes wilting and death mostly in herbaceous plants. Often represent is the "V" in V,F,N in plant tags that denote fusarium resistant.
GallAn unusual and abnormal growth on a plant. Caused by insects, but can also be caused by bacteria and fungi. No harm to the plant material other than it is unsightly.
Garden Designer(Aren't we all?) A person who professionaly will create plans for a home or public space. Many are self-taught, and not generally licensed by the state. Not to be confused with garden architects who are specifically trained and licensed. Garden designers sometimes are referred to as landscape designers.
GenusUsed when naming plants. Genus is the plant equivalent of our surnames. When followed by the name of the "species" you have it's botanical name. Almost always in Latin.
GeotropismNot a commonly used term but it is the response to gravity. Plant parts that grow downward, such as the roots, would be positive geotropism. A negative geotropism would be the stems growing upward.
GerminateThe sprouting of a seed.
GibberellinA hormone used in plant production. Often used in Camellia blooms and in increasing the size of fruits.
GirdlingThe choking of a branch by a wire, rope, or other inflexible material which usually occurs most often in woody stemmed plants that have been tied down too tightly without regard for growth.
GladeAn open space in a woodland area.
Glasshouseour friends the British use this in reference to a greenhouse.
GlenA very romantic term meaning a narrow valley.
GlochidsTiny, still hairs with barbs found in cacti. Don't let them get you.
GradeNot your A, B, C's in class, but the degree or direction of a slope, generally. Real important with house construction and ground placement.
GraftingThis is a method of propagation. The process of joining a desirable stem or bud of one plant (known as the scion) on to the less desirable, but hardier, stem of another (known as the stock). This will give a stronger root system than the scion would have normally had. Commonly done in roses, fruit trees and in some ornamentals.
Granular FertilizerA fertilizer that is dry and is a tiny pellet form. It is spreadable and should be measured. A granular fertilizer can come in both a natural and synthetic form.
Green ManureA crop (such as rye grass) that is grown and then incorporated into the soil to increase soil fertility or organic matter content. Usually turned over into the soil a few weeks before new planting begins.
GreenhouseA house that is green. One would think, but this is a structure that can be build out of glass, plastic, or fiberglass. This building will be controlled in its temperature and humidity. Greenhouses are used for public display, cultivation, and in general protection of plants. Greenhouse comes in hobby sizes and as commercial usage.
GreensandA sediment composed of grains of glauconite mingled with clay or sand used as an organic fertilizer. It contains about twenty-two trace minerals including potash, silica, iron oxide, magnesia, lime, and phosphoric acid. Mined in Florida, once the ocean floor. Roses and tomatoes love it. The material will prolong fruiting and loosen heavy clay soils.
Ground CoverA plant used to provide a low-growing carpet between other plants.
Growing HabitA direction or shape a plant takes as it grows.
Growing PointThe area where the new growth occurs. When a plant is pinched and the new shoots then develop, this is the growing point.
Growing SeasonThe period of time from the last frost date in spring to the first frost date in the fall. Vegetables especially will require a certain amount of days to maturity. Make sure your growing season in long enough.
Growth RegulatorA commercial chemical used by nurseries to change the shape of a plant. In general to dwarf a plant or to make the stems shorter. Kalanchoe are often dwarfed and then forced to bloom. The plant eventually will grow out of this, especially if cuttings are taken.
GypsumA mineral of calcium sulfate. Gypsum adds calcium to the soil. It also will improve the structure of a clay soil. There will be no change in the pH value of the soil.
Gypsy MothA caterpillar about 1 1/2 inches long that came from Europe. these larvae do great damage by chewing and sometimes defoliating the entire tree.
HabitThe shape or form of a plant, growing vertical, laterally, or rounded. It is important to know the habit of a plant so one can expect certain growth patterns.
HabitatThe environment in which a plant is usually found growing, the factors being climate and soil. Microclimates will also play into this.
HahaNo, we are not starting a comedy club, but in the 18th and 19th century the dry moat or ditch around the English Manor house was created to keep animals from roaming too close.
Half-HardyJust as the word depicts, not completely hardy. Good examples re pansies, snapdragons, sweet alyssum. They will tolerate some light frost and cold nights.
HalophyteThose plants that will tolerate salt in the soil. Mostly coastal plants in the dunes, or marshes.
Hardening OffGradual acclimatization to colder conditions. Usually used when taking seedlings out of the greenhouse or moving outside to a cold frame or protected area.
HardinessWhen a plant has the ability to withstand low temperatures or frost.
Hardiness ZonesThis was created by the US Department of Agriculture. The zones are divided into 11 zones. Based on the average minimum temperature in the winter. It is important to note that this has all been revised and good to recheck. Easily found in many books and catalogs. If a plant is recommended for zone four it will grow in tht zone and those higher.
HardpanCompacted soil, sometimes new, created by construction. Water will run off and plant roots can not penetrate the layer.  Can be broken up.
HardscapeIncludes any garden feature that is not a plant. Like birdbaths, deck, fences, trellises, benches, and patios.
HayStems of grass. Most popular feed for horses and cattle, however gardeners are always looking for "spoiled hay" or "mulch hay". This is hay that has rotted or gotten moldy. It is great for compost piles and using as a mulch. Beware of weed seeds and compost well.
Heading BackThe process of cutting an older branch or stem to a twig or stub.
Heart Rotmost commonly heard of in reference to trees. The center merely has rotted out. Can also happen in root vegetables.
HeavingWhen there is a climate change from frost to warming of the soil, it often causes the soil to buckle upward. Sometimes called frost heaves.
HedgeSuitable trees, shrubs, or bushes planted relatively close together so that the branches will intertwine to provide a barrier fence for a windbreaker or privacy. Hedges can be any height or width depending on the plant material used. Generally they are long lived species.
Hedge RowJust as it reads a row of plant material (shrubs and trees) that are suitable for hedges.
Heel CuttingA short, side branch taken as a cutting with a small piece of the main stem. (Often taken with old rose cuttings.)
Heeling-InThis is a temporary planting procedure until a plant can be put in its permanent place. The plant will benefit from the soil temperature.
Heirloom PlantPlants that have been around for 50 years or more. Not all people will consider the same plant an heirloom.
HerbA plant grown for its medicinal or flavoring qualities, or its scented foliage.
HerbaceousA plant with a non-woody stem. The upper parts will die back at the end of the growing season. It generally refers to perennials. Gertrude Jekyll invented the term.
Herbaceous BorderProbably more known in ferns with Gertrude Jekyll as she created great colorful perennial boarders in contrast to previous Victorian annuals in their showy and symmetrical beds. Of great interest and diversity.
HerbariumA collection of dried specimens and a research center. It is a special kind of museum. 
HerbicideAs much as I hate the use of this word and anything connected to it, it is any chemical that will kill a plant. There are both selective and non-selective herbicides. Selectives only killing a specific plant and the non-selective killing a larger segment of plants.
High ShadeAlways a difficult gauge but generally it is the shade beneath trees that have been "limbed up" or pruned to get some light in.
Hill UpIt sounds like an old fashion term but means to pull the soil around the stem of a plant for support.
Honey DewThe sweet and sticky syrup secreted by aphids and other sap-sucking insects. It then sometimes gets moldy fungus on it. Should be washed off with a soapy water rinse.
Horticultural OilThis includes both a dormant oil and a summer oil used to smother eggs and developing insects on trees and ornamentals. The heavier oils are used in the late winter or very early spring, making sure the temperatures are over 40°F but before the plant leafs out. The lighter summer oil can be used anytime the temperature is below 85°F.
HorticultureThe art and science of gardening. Commercial horticulture would include fruit, flower and small scale vegetable growing including the nursery industry. Agriculture covers broad acre farming of plants.
Hortus This plant dictionary was originally created by Liberty Hyde Bailey in 1930. Plants that were and are cultivated in the U.S. and Canada. It has been rewritten by the staff of the L.H. Bailey Hororium at Cornell University. It is definably a reference book to have on your shelf.
HostAny plant material that will support a parasite. Oak trees will host mistletoe that will create damage and oaks can also host Spanish moss that does no harm.
Hot CapCones that are used a lot in cooler zones to protect newly planted seedlings from cold weather and birds. Usually made of plastic or a very heavy translucent waxed paper.
Hot HouseAnother term for a greenhouse sometimes found in earlier garden writings.
House PlantsPlants that are grown in containers inside the home.
HumusThis is the organic residue of decayed vegetable in the soil (i.e. leaf mold or compost.)
HybridThe offspring of two different varieties or species. The pollen of one variety pollinates the variety of another. A new plant is created.
HydroponicsA method of growing a plant in water containing dilute nutrients. Many vegetables are commercially grown this way. Epcot center has a wonderful hydroponics center.
HypertufaLately this has become very popular. A replica lightweight rock material created by equal amounts of dry cement, sand, perlite, peat moss, and water. This is made into troughs, planters, and rock all in the manner of looking old.
IkebanaThe formal flower arranging done by the Japanese. Special attention and thought to balance, harmony, and form.
IndeterminateBeing able to grow for an indefinite period of time (i.e. many tomatoes.)
IndigenousPlant species that are native to that region. These plants are believed to be growing in the wild at least for the span of human history.
Infertile Soil that has no nutrients.
InflorescenceThe arrangement of flowers on the stem. Basically, a flower head.
InorganicA chemical or fertilizer which is not obtained from a source which is or has been alive.
Insecticidal SoapA great alternative to using chemicals on plants. It may not be the total answer to getting rid of insects but certainly should be tried first. A homemade version is two tbsp. to a gallon of water. Several application may have to be used.
InsecticideA synthetic or organic chemical used to kill or repel insects. Please use as directed on the label.
Insectivorous PlantAnother term for carnivorous plants. Plants that will trap and digest insects that will supply them with nitrogen. Most of these plants grow in swamps where it is difficult to obtain nitrogen.
InsituThe act of sowing seeds or cuttings in the ground where they are to grow.
INTERCROPPING Or INTERPLANTINGA smart way to garen. Mixing two or more plants, tall and short, for foliage difference, or combining plants that bloom at different times of the year.  It keeps the interest in the garden.
InvasiveThe ability of a plant to spread quickly and will crowd out other plantings Great for a ground cover but dangerous for a well kept, under control garden bed.
IpmIntegrated Pest Management. A method by which gardeners can learn to manage and eradicate pests by choosing appropriate plants providing good growing conditions and minimizing pests rather than annihilating them.
Iron ChelateThis is often recommended when plants are showing signs of chlorosis. It is a form of iron, being readily absorbed by plants, especially in alkaline soils.
Japanese BeetleIf there is one bug a gardener should know it is the Japanese beetle. Its larvae in the soil is known as the white grub that will eat the roots of your grassy lawn. When the beetle appears it eats its way through plants especially roses and leaves them like skeleton forms.
Japanese GardensGardens that are designed with a Japanese cultural influence. Using particular plants for the design. Often with a Zen influences. Bamboo, pine, mondo grasses, koi are often used.
KernelThe edible part of nut.
Knot GardenA very carefully planned garden of small dwarf shrubs or even herbs. Planned in a pattern and kept in order by constant pruning and trimming.
LacewingThink beneficial. About one inch in length will eat mites, aphids, and thrip.
Landscape ArchitectA very good professional to consider when creating a garden. They are licensed by the state and know the mechanics of major construction, grading, drainage, and will advice solutions to problems.
Landscape FabricProbably one of your best solutions against weeds for beds. This can be a variety of materials: newspaper, plastic, porous fibers, burlap. It provides a barrier for weeds to germinate. This is then dressed with mulch of any kind.
LathA structure used to create shade. Made of any material, evenly spaced to let in some light.
LayeringA way to propagate plant material. A branch is anchored to the ground (still attached to the parent plant). Roots appear creating another plant.
LeachingA process which can rid soils of bad substances, like salts.
LeaderThe main growing shoot of a sapling, it eventually will become the trunk of the tree.
Leaf CuttingA method of propagation. A leaf is removed and is placed in vermiculite or perlite for future baby plants.
Leaf MoldPartially decayed leaves used in some potting mixtures. It must be sieved and sterilized before use. Great for outdoor use in beds.
Leaf RollerDifferent moths that will roll leaves when larvae. Cannas often get a lot of leaf rollers.
LeafletA leaf-like section of a compound leaf. Small in stature.
LeggyThis is tall and spindly growth, not usual to the growth habit of the plant. It is seen because of the lack of light.
LegumeA plant whose roots form an association with soil borne bacteria that can capture atmospheric nitrogen. A good example of this are soybeans.
LichenA combined growing condition of algae and fungus. It looks crusty, and comes in many colors: gray, green, bluish, or browns.
Limbing UpPruning off the lower limbs of trees, usually for ease of walking underneath or admitting sunlight.
LithophytePlants that grow on rocks or other areas that do not need soil. They will receive their nourishment from the air. i.e. orchids and lichens.
LoamGood quality soil. Adequate supplies of clay, sand, and fiber must be present. Crumbly to the touch. Ideal for most gardening.
ManureAny animal droppings with a high content of nitrogen, these should be composted and aged before use. Take special note not to use cat or dog droppings. All to often these contain disease organisms.
Manure TeaA liquid fertilizer made by mixing manures with water and filtering out. Pillow cases filled with cow or horse patooties and dunked in a pail of water.
Marginal PlantPlants that will grow on the edges of ponds or lakes and when cultivated will make nice plants around a water garden (i.e. iris).
Mass PlantingThe planting of one particular flower or many of the same kind somewhat close together to create a dramatic "look".
Master GardenerCounty residents who volunteer and are trained to work with the extension service. (see article).
Micro PropagationAlso called propagating by tissue culture. Taking cell slices of plant material and starting growth on culture dishes.
MicroclimateA physical area with a set of conditions different from those surrounding the area.
MicronutrientsThese are the very important nutrients that plants need for proper growth. Carbon, hydrogen, oxygen, and from the soil they will acquire nitrogen, potassium, and phosphorus and in smaller quantities calcium, sulfur, and magnesium.
MicroorganismsAnimals and plants that are too small to be seen clearly with the naked eye but are the soil enablers helping to improve the dirt.
MildewSeveral different types of fungi. Two popular types are downy and powdery. It leaves a white coating on the leaves. Common to crepe myrtle, zinnias, grapes, and roses even bee balms. It shows up in cool, wet weather. Drip irrigation can prevent some occurrence. Plant disease resistant varieties.
Mist PropagationThe ideal method of propagation in a green house or place with good circulation, using automatic misters.
Mixed BorderSome of this, some of that in a border. Shrubs and woody plants that are still in the bed when the annuals and perennials are gone for the season.
Moist But Not WetPlants that grow well in moist conditions but not entirely wet. Whether it be in the ground or in a container.
MonoeciousA plant which bears both male and female flowers. (Compare to Dioecious)
Moon GardeningA very romantic night garden created by using white night flowering plants or light variegated leaf varieties of plants. Really a pretty effect.
Mowing StripSometimes known as an edging strip. The six to eight inches of space between the lawn and the flower or vegetable bed. The flat area decoratively made with cement or brick.
MulchAny loose, usually organic material (can be small pebbles) over the soil as a protective covering or for decorative purposes. Common mulches are ground bark, saw dust, leaves, pine straw or eucalyptus.
MutationAny change in a plant which will lead to a new feature. Fortunately or unfortunately, this can be inherited.
NativeThis refers to a plant that grows in the same habitat in which they originated. These plants can be native to a continent, state, or region.
NaturalizedPlants that will behave like native plants in a given geological region. Bulbs naturalize nicely and lend themselves to a blooming statement.
NectarA sugar and water substance secreted by flowers, this will attract pollinators like bees and hummingbirds searching for food.
NeemA botanical insecticide that is nontoxic. It is derived from the neem tree (azaderachta indica).
NematodeA microscopic roundworm that lives in the soil. There are both harmful and beneficial nematodes. Harmful ones take their toll on the roots of a plant.
NeutralThis is neither acid nor alkaline; pH 6.5 - 7.5.
New WoodA term often used in reference to propagation. That part of the stems and branches that have grown during the current season. Some plants will propagate better on new wood as opposed to old wood (previous season's growth.)
NodeThe point on a stem where a leaf or bud is attached; the place for which propagation is used.
Node AnchoringNode anchoring or node cuttings are when you take a cutting of a stem right below a node. This is a better method of getting success than taking a cut just anywhere on the stem. It is mentioned for the Persian Shield because the success rate for stem cuttings for the Persian Shield is not that great and cutting right below the node gives it a better chance.
NurserymanOne who is state certified to practice growing techniques of plant material making the proper selection for specific needs.
OffsetA young plantlet which appears on a mature plant. An offset can generally be detached and used for propagation as in spider plants or walking iris.
Open PollinatedAny plant that has been pollinated in the field. In direct contrast to hybrid varieties that will grow true to variety the plants produced will be true to the parents.
OrganicFertilizers and chemicals that have been obtained from a source which is or has been alive. Also the general term used for a type of gardening using no chemical or synthetic fertilizers or pesticides.
OrnamentalA plant that is grown strictly for its foliage or flower rather than for food or any other economic use (i.e. saucer magnolia.)
Over PottingRepotting a plant into a pot which is too large to allow successful establishment. The roots may die from too much moisture.
OverseedingPlanting on top of an existing garden or lawn. Rye grass over lawns for winter. Wildflower seed in meadows. 
Palmate LeafFive or more lobes arising from one point hand like.
ParasiteAny plant that grows upon another. It steals its moisture and nourishment from its host. Mistletoe is a good example.
ParterreSymmetry at its best. These are great ornamental garden beds that have been geometrically designed and separated by walkways. The gardens are most appreciated by an above view. One of the most famous being the gardens of Versailles.
Passalong PlantsPlants that are shared between friends and not easily found in catalogs. Usually some plant from an older garden.
Pea GravelGravel about the size of a pea. Used a lot in driveways and walkways.
PeatThe preserved and compressed remains of dead bog plants. Often known as peat moss because it is from sphagnum or sedge peat.
Peat PotCompressed peat into a pot that can be used for starting seeds. When planting times comes this entire pot can be put in the ground and the roots will grow through the pot as it decomposes. 
Pebble TrayA tray filled with pebbles to create humidity in the environment. Continual evaporation will take place up and around the plants.
Pegging DownA very effective way to increase flower production on Bonbon & Hybrid Perpetual roses that send up long shoots with oily flowers on the end. It is a time consuming method but well worth the display. This is generally done in the fall. Instead of pruning, spread the runners and fasten to the soil with wire loops. Basically you are training the plant horizontally. 
Pelleted SeedsSeeds that have been coated with an inert material just to make the handling of the seed easier.
PerennialA plant which will live for three years or more under normal conditions.
PerfoliatePaired leaves which fuse around the stem.
PergolaSometimes called an arbor, or walkway covered with trellis work. Usually climbing plants will cover the hardscape feature.
PerliteGranular volcanic rock, used to improve the aeration in potting soil. No nutrient value.
PermacultureA very advanced system of trying to grow and provide food by using perennial plants instead of the annuals the agriculture world uses now for most of our food.
PetalOne of the divisions of the corolla generally the showy part of the flower.
PhThe scale where the acidity and alkalinity of soil is measured. It starts at "1" for acid and goes to "14" for alkali. Most gardens will fall between 5.5 & 8.6.
PhotoperiodismThe response of plants to the length of a day and night (i.e. poinsettias, cactus, night blooming flowers)
Pinch OutPinching with the fingers to remove the tip of a growing shoot to encourage lateral growth. 
Pioneer PlantsThe very first species to grow of the soil has had a traumatic occurrence, like a fire, flood, earthquake. The first plants to take over when a farmstead has been abandoned.
PipUsed in propagation. The side offshoot of a rootstock. A good example is lily of the valley.
Plant LiceThis is a reference to aphids found in British publications.
Plant Patent NumbersThis generally is a catalog referral phrase. For the general gardener it may not be important but new plants, like inventions, can also be patented. This is a protection for the owner who created the "new" plant.
PlantletA small plant off the original plant. A good example is the piggy back plant these will easily root. Used in propagation.
Pleachinga popular technique of training and pruning shrubs and trees into a wall. Very popular in Europe.
PlugA small but well-rooted seedling raised in a cellular tray for covering large areas as in ground covers or lawns.
Pocket GardenA small growing area planted with miniature and dwarf varieties.
PollenThe yellow dust produced by the anthers. The male element which fertilized the ovule.
PollinatorWho are these wonderful creatures that make our world grow? People, bees, moths, butterflies, bats, and any insect that hops from plant to plant.
Pot BoundA plant growing in a pot which is too small to allow proper leaf and stem growth. Roots will start to grow in a circle in the pot.
PotagerGiving credit to the French who inspired this vegetable garden. It is planted in a formal and ornamental style.
PotpourriA mixture of sweet smelling leaves, petals, blooms to create a perfume in a room. Tussie massies in the Victorian era were popular nosegay potpourri creations.
Potting UpTaking the young seedlings or transplants into a specific container for mature growth.
Prairie GardeningSpecifically creating a garden of plants from the Midwestern states of the U.S. Most associated with the designer Jens Jensen.
Pre-Emergent Weed KillerA great idea is good gardening.  Although not organic, this is using a herbicide to kill the weed seeds to prevent them from germinating.
Pressure Treated LumberLumber that has been treated with chemicals to prevent rotting.
PropagationFor gardening methods, this refers to the many different ways of starting new plants.
PruningThe cutting off leaves or branches within limits in order to remove dead or diseased foliage or branches. Also used to control or direct growth, increase quality or yield of flowers or fruit, and to ensure growth position of main branches to enhance structural strength.
RadicumsThese plants are special in that their stems have roots that will cling as they grow vertically or grow over the ground. Ivy is a good example.
Raised BedAny ornamental or vegetable bed that has soil higher than the surrounding immediate area. Sometimes it is bordered by boards, stone, brick or any material to hold in the soil. Created to make a supreme growing area.
Re-SeedingPlants that drop their seeds for next season. Called "easily re-seeders". Wildflowers and weeds are the biggest categories.
ReedTall grasses that grow in shallow water.
RemontantRepeat bloomer. Plants that will bloom more than once a year. Tea, olive, daylilies, or bottle bush.
Resting Periodmostly in terms of bulbs, it is a period of dormancy where energy is restored to the plant.
Retaining WallA wall that has been built on a slope to keep the soil from sliding or eroding. It would stabilize the area.
RevertSometimes a particular cultivar might change back to one of its original species. I.e. Variegation going to solid green, some doubles going to single.
RhizomeA thickened stem which grows horizontally below or on the soil surface, as in iris rhizomes.
Rock GardenAn area constructed of larger rocks arranged to look natural. Planted with plants that generally do not need a lot of care.
RockwoolThis really is the state of the art rooting medium, and is used in plant propagation. It is alkaline and one will have to compensate for this.
Root BallMatted roots plus enclosed soil within the pot of a container grown plant or when plant material is transplanted.
Root CropsAny vegetable that the roots are edible: i.e. carrots, potatoes, turnips.
Root Cuttingthe root is used for propagation. Plants that grow away from the mother plant and root, can be dub up and transplanted.
Root PruningThis is done in two instances. One when repotting from one pot to another, roots that have grown in a circle are trimmed to promote future growth. Also, when planting into the garden or landscape, a plant that needs root trimming.
Root RotQuite common in plants that are effected by fungus diseases and have poor drainage.
Root ZoneThe entire area where roots are growing below the plant. Root zones are important for walking paths and future plantings.
Root-BoundOften, when plants are left too long in their container, the roots become entangled and begin to grow in circles. There is hope by separating the roots the plants will survive when planted.
Rooting HormoneA chemical in powder or liquid form which promotes the formation of roots at the base of a cutting. Contains hormones and anti-fungus growth prohibitors.
RootstockThe roots and stems arise from this part of the plant.
RosarianThose hobbyists or professionals who specialize in the cultivation of roses.
RotationSpecifically towards crop rotation: changing the plants in the same growing area. This will decrease the soil born diseased.
RotenoneMaterial used a lot by organic gardeners. It is derived from the roots of tropical legumes. It does break down in sunlight and the side effect is that it is toxic to good and bad insects.
Row CoversAny type of semitransparent materials used to cover plants, trap heat, enhance growth, and provide protection from frost or winds. Commercial growers sometimes use this method.
RunA plant that runs will be growing rapidly underground. Great for ground cover but some plants take over an area by running.
RunnerA creeping stem which produces small plantlets along its length. Sometimes called a "stolen".
RunoffWhen liquids (such as in watering an area of ground or a fast rain) washes off quickly a run off is created. Often pesticides and fertilizers are washed into waterways from lawn and garden runoff.
Salt Marsh Hayprobably a better mulch that is collected from the grasses grown in coastal marshes. It generally does not contain weed seeds and is fluffy.
Sapthe fluid in plants . Most know is the collecting of maple sap made into syrup.
SaplingA very young tree.
ScaldWhen plants have an overexposure to sunlight a discoloration will develop. Often when plants do not become acclimated slowly into a sunny location from being indoors or from the shade.
ScaleSucking insects. Usually more prevalent in milder climates. Not to be taken lightly, and need to be treated.
Scapea leafless flower stem that will grow directly from the base of the stem. Very common in bulbs.
Scarifyto scratch or break the hard coat of some seeds, so they will germinate easily. Fine sandpaper or just soaking the seed will do the trick.
Scientific NameThe internationally recognized Latin name of a plant that will be descriptive of the feature of the plant, or will commemorate a person connected with it. The name of the species will consist of two parts, the genus name and the species name. This system was first started in 1753 by a Swedish botanist, Linnaeus.
ScionA suitable piece that is a desirable specimen of a woody plant, used in grafting.
SCOOPING (De-Eyeing)A technique that is used to produce a shorter and bushier plant by scraping out the center eye of the bulb.
SeedheadDried, inedible fruit that contains seeds.
Self PollinationThe transfer of pollen from one flower to another flower on the same plant.
SELF-SEEDED, Or SELF SOWINGA plant's habit of shedding seeds in the immediate area. They will then germinate without outside help. Many annuals use self seeding (i.e. cleome-marigolds).
Semi-EvergreenThose shrubs that will keep some of their green foliage usually in mild climates.
SetIn reference to shallot bulbs and small onions, as in sets of onions.
Sharp SandAh, also called builders sand. This sand is rough. Great for drainage, and propagation, not to mention starting of seeds.
ShearA method of pruning in the landscape. Often in reference to hedges.
Sheet CompostingA method of piling un-decomposed organic materials over the soil and waiting for decomposition. At times working it in the soil.
ShrubA woody plant with a framework of branches and little or no central stem. Compare to tree.
Side DressWhen one fertilizes above the ground without working it in. Placing the fertilizer on the side of the plant material. Sometime side dressing is used to encourage growth during the season.
SieveA garden sieve is a frame with a mesh bottom. Mainly used for separating compost, but sometimes used in very stony gardens. Home made ones made out of two by fours, 2' x 2' with a 1/2 inch hardcloth bottom is most handy.
SlipAn older fern once used for a cutting. Slips are taken for propagation.
Slow Release FertilizerGenerally a natural fertilizer that over a period of time will release its nutrients. Always a good practice to use.
Soaker HoseHoses that have hundreds of mini holes to let the water out slowly and can be left on for a long period of time. Great for vegetable gardens and beds that need to be watered frequently.
Soil AmendmentAnything added to the soil to improve the present situation, i.e. drainage, nutrients, or makeup.
Soil Less GardeningAnother name for hydroponics. Gardening in something other than soil or water and rocks.
Soil Less MixThis would be any medium for containers. The substances would be like peat moss, perlite, vermiculite, or materials like sand or bark. However,  fertilizing is a must since none of these have any real nutrient quality.
Soil PolymersSuper absorbent polymers that have been around for a while, that can be added to retain moisture containers. It will absorb many times over its weight in water. Use sparingly.
SolarizationThe process by which one can sterilize the soil by the sun. Cultivate the area to be isolated, water well, and then cover with 2 - 4 mil of clear plastic.
Soluble FertilizerA fertilizer that is mixed with water and used not only for root fertilizing but can also be sprayed on the foliage. A common practice for houseplants but gardeners can use the practice in their landscape too.
Sooty Mildewis a fungus. It looks like a dark gray spots or in general scum on stems and leaves. It is formed from the honey dew excreted that is produced by aphids and other insects. The honeydew that is created is attacked by the mildew and will go after the sugars in the honeydew.
Sooty MoldSeveral insect pests will release honey dew, which is a sticky substance that then mold grows on (thus the black coloring). Most associated with aphids. Use a soapy water solution to rinse off the insect pest.
SpeciesThis is a group of plants that have common characteristics. It is a basic unit of plant classification.
Specimen PlantA plant that is high lighted to show off its special qualities. Sometimes used as a focal point. 
SpentBulbs and flowers of a plant that have finished blooming. It's time to deadhead them.
Sphagnum MossMany mosses native to bogs are sphagnum. Used for the lining of hanging baskets and for air layering (i.e. Spanish moss.)
Spicesseeds, fruits, or roots (rhizomes) used to flavor cooking.
SporeA microscopic reproductive cell of non-flowering plants (i.e. ferns, lichens, mosses, fungi, and algae). Many times we can see spores on the backside of ferns.
StakingPlants that grow tall with little stem support need to be staked. Perennials and tomatoes come to mind. Any means of support will work: canes, cages, wire loops, etc.
StandardThose plants, especially roses, that are grown so all the branches are brought to a head on one single stem. A standard can also be a full size fruit tree. This is done strictly for esthetics.
Stem CuttingA portion of a stem that only includes one or more nodes taken from a plant. This will not include the apex or the tip. Stem cuttings are a great way to propagate.
Sterilized SoilIt is soil that is steam- or chemically sterilized. Harmful organisms have been killed but helpful bacteria have been spared. Sold commercially.
StigmaThis is the part of the female organ of the flower which receives the pollen.
StockThe "mother plant" of which cuttings are taken.  Stock is also in reference to plants being grafted on "stock". Many hybrids are grafted on good stock material because they have better and sturdier qualities for growing.
StoneThe inner fruit wall of a drupe. The stone encloses the seed (i.e. plums and cherries).
Stretching The ZoneFor very ambitions gardeners who want to grow plant material beyond their climate area. Collectors are forever trying to grow what might not. (see zone article)
SubtropicalVery specific area, 5 to 10 degrees higher in latitude than the Tropic of Cancer of the Tropic of Capricorn.
Succession PlantingWhen one plants a fast crop one week or so after another. The object is to keep a constant supply on hand, like squash, lettuce, truck farmers often practice this technique.
SucculentSucculent plants have leaves and/or stems which are thick and fleshy. They often have waxy outer layers that allow the plants to retain water well.
SuckerA shoot which arises from an underground shoot or root of a plant.
Sun ScorchSpots on leaves that are caused by exposure to strong sunlight. Often not acclimating plants for the season creates sun spots. Just trim off and let new growth develop. 
Sunken GardenA landscape design where some of the garden is at a lower point than the rest of the garden. Created for interest.
SwampAn area of land that usually flooded and contains woody plants compared to a bog it has drainage. Cypress trees grow well in a swamp.
Systemic InsecticideA pesticide which can be granular or liquid, used at the base of the plant and travels through the vascular stream.
TampingA method by which one will press that soil around a plant that has just been planted making sure soil is secure and firm around the roots.
Tap RootThe main root, sometimes swollen, which grows vertically into the soil. It is hard to transplant perennials with tap roots.
TenderAn indoor plant which requires a minimum temperature of 60°F. Occasional short exposure to temperatures below this level may be tolerated. 
TendrilPlants (like sweet peas, clematis, and grapes) producing a cordlike structure that will help to support themselves.
Terra CottaAn Italian term that means "baked earth". These clay pots are unglazed and excellent for growing most plant material. They do dry out quickly and salts will bleed through the porous surfaces. Emily Compost's most favorite growing container.
TerrariumsAny transparent container with a cover so plants may grow. Sometimes called a bottle garden and in the early 1900's Victorian era called Wardian Cases.
TerrestrialA plant which grows in the soil as opposed to aquatic or perched on trees.
TeteurA French word meaning "trainer". Any structure that is in the shape of an obelisk or pointed tower. This trellis will support vines of color.
ThatchAny material that does not quickly decompose. When a lawn becomes "clogged" with old drying grass cuttings and matted leaves, this is referred to a build up of thatch. Often it does not decompose fast enough for a healthy lawn and needs to be removed, either manually or by a thatching machine.
ThicketAny area that has a lot of miscellaneous undergrowth, generally of small shrubs, bushes, and vines.
THIMBLE And THUMB POTSNot generally spoken of a lot in the United States, but in Britain are interesting miniature clay pots. Thimble pots are 2 x 2 inches and thumb pots are 2.5 x 2.5 inches.
ThinningPicking out the overpopulated seedlings in any flower or vegetable bed, to make a better growing condition for the rest. Making better spacing and esthetics for the growing area.
ThripsInsects that feed on all parts of the plant: leaves, flowers, buds, and stems. Very popular in the destruction of daylilies (this word is both singular and plural).
ThugNot your normal street gangster, but close to it. Thugs are invasive plants. We enjoy their attractiveness but they will take over a garden. They are growing in the right conditions, but ironically thugs can make a statement when they are perennials in the right garden.
TillAnother definition for cultivating. Plowing the earth and preparing it for planting.
Tip CuttingA cutting taken from the top end of a shoot.
Tired SoilA term referring to a piece of land that has been exhausted of its nutrient value. It does not produce like it once used to. When a particular crop has been grown too long in once place. The Southeast U.S. created tired soil from planting cotton for too many years.
Tissue CultureA very sterile practice of propagating plants from the mother plant. Generally done in laboratory conditions. Orchids, hosta and daylilies are done by this method.
TopdressA process that means to apply on the surface of soil. Usually referring to the spreading of organic material such as ground bark or manure, compost, or fertilizer.
TopiaryThe horticultural art of clipping and training woody plants to form geometric shapes or interesting patterns.
TopsoilSoil that is on the very top, hopefully containing a lot of humus and good elements needed for growth.
Trade NameAn arbitrary name created by a nursery or some other organization to distinguish it from all others a way of protecting it from misuse legally.
TrailingAny plant that grows long stems and will grow along the ground and will root as it goes along.
TranspirationThe loss of water through the pores of the leaf.
Treated SeedsSeeds that have been protected against diseases. They are toxic.
Tropical PlantA plant that grows in tropic zones. It is what northerners make up as houseplants.
TrugWe must include the "English basket". It basically is just a shallow basket for light chores, like carrying flowers and fruits and veggies. Traditionally made out of wood. Very functional.
TuberA storage organ used for propagation. It may be a fleshy root (e.g. Dahlia) or a swollen underground stem.
Under GlassA term in older books referring to "growing under glass", essentially growing in a greenhouse.
UnderplantingGrowing short plants such as a ground cover under taller plants. Under taller trees, some shrubs would be used as an underplanting.
UnderstoryThe smaller trees that grow below the major forest.
Variegated LeafA green leaf design which is blotched, edged, or spotted with yellow, white, or cream color.
VarietyOne of possibly many closely-related plat species. The variety name is usually in Latin.
Variety NameThis is the scientific name or botanical name of a specific plant. It is in italic print.
VegetationAn all encompassing word for the plants of an area or territory.
VermiculiteA light-weight, mineral called mica that is added to potting mixtures to improve root growth via aeration and has moisture retaining abilities. There is no nutritive value in the mineral.
VernalizationThe time factor of cold days needed by certain plants to produce a bud. Such as in apples need a certain amount of cold days to create their buds.
VerticilliumA fungus disease that will cause wilting and death. This is the "V" in "V,F,N".
VfnIndicate whether or not a plant is resistant to verticillium wilt, fusarium wilt, or certain nematodes. Many times all three.
ViabilityThe possibility of germination. Seeds vary in their time of viability from a few days to 20 years, if not hundreds of years. Storage conditions will affect the viability, the best being low temperatures and humidity.
Victory GardenHomeowners during World War II, who grew gardens to provide for themselves or to support the war effort.
VirusA plant disease that cannot be eliminated by a chemical means. Some viruses have created stripped tulips. Most are feared by growers.
VolunteerAlthough this could be your best friend, helping out once in a while in the garden, this is a "not planted" specimen blown in from a neighbor's yard or a surprise, from a bird or other source.
Wardian CaseIn the 19th century a plant explorer and collector by the name of Dr. Nathaniel Ward designed a glass case to transport his findings. He traveled between Australia and England. During the Victorian era often Wardian Cases were highlighted in the home. We now have terrariums and bottle gardens.
Warm Season GrassThese grasses are grown in temperatures above 70 and 80 degrees. They will go dormant in winter. Examples are Bermuda grass, a variety of St. Augustine. Other warm season grasses are ornamental such as pampas grass and fountain grasses.
Water GardenAny man made pool, forms, or container that aquatic plants are planted. They especially are becoming popular in the 21st Century fo r backyard enjoyment.
WeedAn uninvited guest in gardens.
Wet FeetA condition when the roots of plants are in standing water. They will eventually rot if they don't normally grow in wet conditions like aquatic plants.
Wetable PowderA material that will not dissolve in water, but remains suspended in it. Most often referred to pesticides when used as sprays.
WhipA very thin shoot with no lateral branches of a woody plant. Sometimes the first year of a grafted tree.
Wide Row GardeningA method in which vegetables and cutting gardens are laid out usually two to three feet wide instead of a single file row of plants. This is to be efficient in spacing the plants. Many plants grow together.
WildflowerPlants that can be native or exotic when growing out in a non-cultivated area. They flower and are enjoyed by all. Many wildflowers of course can be cultivated in backyard gardens.
WiltA plant disease. This can be caused by bacteria or fungi. Many are carried by insects.
Wind BreakA purposeful planting of hedges and trees to protect a field, home, or garden against forceful winds, providing a shelter and preventing damage.
Window BoxA container placed under a window, very cottage-like in gardening decor.
Winter KillA condition that happens when plants have not hardened enough to withstand sever winter conditions. The plants may not be hardy for the zone. Die back needs to be pruned in the spring clean up.
Woodland GardenThis garden is usually established beneath deciduous trees. It may vary from partial to deep shade and usually with plant material where roots need to remain undisturbed.
Woody PlantThese are usually perennial plants (i.e.. vines, shrubs, trees, and bamboos) that have permanent stems. These branches get bigger every year.
WORM (Eisenia Foetida)A very unappreciated mover & shaker of the earth. Mother Nature's natural composter.
XeriscapeThis is a patented name that stands for a landscaping method that is based on low water volume and drought adaptable plants..