Glossary of Gardening Terms
The language of gardeners and farmers

THE GARDENERS' LANGUAGE

A concise glossary of gardening words you should know

The listing of gardening terms below is brief but concise. It includes a number of terms that a gardener should be familiar with so they can knowledgeably talk with nurserymen or other amateur gardeners.

Actual: (as in actual nitrogen). A term commonly used by farmers and soil scientists that is also useful in everyday gardening. It means the portion of a manufactured fertilizer (or any product containing several ingredients) that supplies a specific needed element. A 25-pound bag of fertilizer containing 22 percent nitrogen will yield 51/2 pounds of actual nitrogen (25 pounds x .22=5.5 pounds).

Annual: A plant that completes its life cycle in a year or less. Seed germinates and the plant grows, blooms, sets seed, and dies—all in one growing season. Marigolds or zinnias are annuals. You may hear or read the expression "grown (or treated) as an annual." This means that you set out a plant after the last spring frost, then discard it when the first cold weather damages or kills it. The plant may normally live through more than one season in a milder climate.

Broad-leafed: Used in the phrase "broad-leafed evergreen," it means an evergreen plant with wide leaves instead of needlelike leaves. Used for weeds, it means any weed that is not a grass.

Bulb: Onionlike cluster of swollen underground leaves.

Cane: Normally used in speaking of the thick vertical stems produced by roses and such berries as blackberries and raspberries. Canes sprout from the ground, or from the base of the plant.

Chilling requirements: Many plants require certain amounts of cold weather in order to produce flowers and fruit, or even to leaf out properly. Some examples are cherries, lilacs, and peonies. If your winter climate is warm, ask your nurseryman for advice before planting such plants. Sometimes varieties exist that will grow well in warm areas.

Chlorosis: Yellowing of leaves caused by iron deficiency.

Composite family: Those plants whose flowers are daisy or asterlike. Each "petal" of a daisy is actually an entire tiny flower, called a ray flower. Other tiny flowers cluster to form the compact center of the bloom and are called disc flowers. Other examples of composites are chamomile, dahlias, marguerites, marigolds, and sunflowers. Chamomile is a composite that often produces only disc flowers in a buttonlike head.

Conifer: Plants such as juniper, cypress, fir, and pine that are sometimes called evergreens. Several are not evergreen, but all produce seeds in a conelike structure.

Corm: Swollen piece of underground stem.

Crown: Portion of a plant at the joint of the root and stem or trunk. Sensitive to rotting if kept too moist.

Cultivate: To break up the soil surface around plants, removing weeds as you go. The resulting rough surface allows air to circulate and helps retain moisture.

Deciduous: Plants that lose their leaves for a season. On most plants and trees, the leaves die in late fall, but some desert plants drop them in summer to protect themselves from too much heat.

Double flower: A flower where the petals are numerous and clustered so that the center is covered by petals. Most hybrid roses are double.

Drainage: The term describes how water passes through the soil. The soil is well drained if water disappears from a filled planting hole in a few minutes. If water remains in the hole after an hour, the soil is poorly drained. The water itself does not damage the plants, but standing water drives out oxygen from the soil so roots may suffocate or be attacked by moisture loving organisms that cause rot.

Dust: A chemical product in the form of extremely fine powder, used to control insects or disease organisms. You apply by blowing the powder from a special applicator in windless weather. It forms a cloud that settles on the plant. Since it requires no mixing or water it is convenient to use; however, you never should try to apply it in windy weather.

Established: An established plant is one that is firmly rooted and is producing a good growth of leaves. But remember that an established container plant, such as one you buy from a nursery, must have time to reestablish itself after you transplant it.

Evergreen: A plant that never loses all of its leaves at the same time. Examples are pines, citrus, rhododendrons, and agapanthus. The term is often used as if it meant only the conifer.

Eye: Usually, the undeveloped buds on tubers which will sprout after the tuber is planted. Common potatoes have eyes in slight depressions over their surfaces. The word may also refer to any leaf bud which is completely undeveloped, such as those at the joints of a new hardwood cutting.

• Bract. Modified leaflike structure that grows in a flower cluster or encircles a flower. Some are more striking than their flowers. The white cone of a calla is a bract.
  
  
• Sepal. The outer circle of flower parts; for example, the green covering of a rosebud. Sepals may be colored as well as green. If they are united, the structure is called a calyx.
  
  
• Petal. The second circle of flower parts. If petals are joined, the structure is called a corolla. The corolla may flare, as with petunias; or it may be bell or tube-shaped, as with various campanulas.
  
  
• Segments. Lilies and tulips show no difference between sepals and petals, so both are called segments.
  
  
• Spurs. Projections from the rear of the flowers, arising from either sepals or petals. Columbine has spurs.
  
  
• Stamens. Parts of the central flower that produce pollen. Stamens are usually fragile stalks with pollen-covered swellings at the top. The stalks are filaments, the swellings anthers.
  
  
• Pistil. The central part of the flower. It is often visible as a stalklike tube with a moist or sticky end. The tube is the style and the end is the stigma. At the stem end of the style is the ovary, the part that may produce seed and fruit.

Forcing: Causing a plant to grow or bloom more rapidly or earlier than normal. Forcing may require extra heat, controlled light, or other special techniques.

Fronds: In the strictest sense, refers to the foliage of ferns, but the word is sometimes used to designate any foliage that looks fernlike, and also the featherlike leaves of many palms.

Hardy: In gardening terms, the word means resistant to damage by cold weather.

Heading back: A pruning term for cutting a branch back to a bud or side branch to change the direction of growth or force bushiness.

Heeling in: Temporary storage of certain plants by burying the roots in soil or sawdust. You might heel in bare root trees for a few days while waiting to plant; or you might lift bulbs while leaves are still green, then heel them in until the leaves die and you can store them.

Honeydew: A sticky, sweet substance produced by aphids and related insects. It may drip from trees, leaving sticky dirt on paving or cars underneath, and it sometimes supports the growth of a black fungus that spoils the looks of a plant.

Humus: Soft brown or black substance formed by vegetable matter in the last stages of decomposition.

Iron chelate: A compound containing iron in a form that plants can easily use.

Leaching: Pouring water through soil to dissolve and carry away soluble minerals that might otherwise damage plants. To leach, water slowly for a long time, or set containers in water and let soak. Leaching will also wash away nitrogen compounds that plants need, so feed after leaching, not before.

Leaflet: Some leaves are divided into several small parts in a feather or fan pattern. Rose leaves are divided into from three to seven leaflets.

Loam: Soil (often dark colored) that is rich in organic material, does not compact easily, and drains well after watering.

Node: A joint along a plant stem where a leaf or branch may grow.

Organic: In gardening terms, organic refers to any material that was once alive, or that comes from a living creature. Sawdust, compost, bone meal, guano are organic, while perlite or ammonium sulfate are inorganic. In the term "organic gardening," organic refers to gardening without chemical sprays or manufactured fertilizers.

Perennial: A plant that lives more than two years, but usually not including large woody plants, called shrubs. However, some perennials are shrubby, while some shrubs are rather soft and fragile. In this borderline area, the term sub-shrub is sometimes used.

Pinching: Removing the tips of twigs and branches to force bushiness. Called pinching because you use your thumb and forefinger rather than a tool.

Plant classification: Botanists (and other biologists) use a standard system for grouping and naming living creatures. This system of names can be useful to an amateur gardener, since a single common name often refers to a number of different plants. The terms below are those most useful to a gardener, although only a part of the whole system of names.

• Family. Every member of a family shares some characteristics, although individual plants may look quite different. In the rose family are such plants as cherries, pyracantha, roses, and strawberries. The lily family includes onions, tiger lilies, and yucca plants. Sometimes many members of the same family are prone to the same disease, even when they are externally different. They may also share cultural requirements.
  
  
• Genus. The plural is genera. The first word in a botanical name is the genus to which the plant belongs, for example Rosa, Prunus, Viola. Occasionally this name is also the common name as with Anemone, Narcissus, or Sequoia.
  
  
• Species. A genus often contains many close relatives, or species. A species is a single kind of plant, although there may be differences in appearance within a species.
  
  
• Viola odorata is only the sweet violet, although it has a number of flower colors and forms. Viola cornuta is the viola, while Viola tricolor is the Johnny-jump-up.
  
  
• Variety. A variety is some special form of a species. It is almost like other plants of its species, but may have a different flower or plant shape. Viola tricolor hortensis is the large flowered pansy.

Pollination: Pollen from flower stamens must be transferred to pistils for fruit and seeds to develop. This straightforward process is complicated for a home gardener by the fact that some plants have male and female flowers on separate individuals (holly), or separate male and female flowers on the same plant (cucumber), or mixed flowers with pollen that is useless on plants of the same variety (sweet cherries).

Rhizome: Swollen root of certain plants.

Root bound: A plant is spoken of as root bound when it has remained in a container for so long that the roots grow around it in a circle. Seriously root bound plants are useless for planting in the garden since their roots will not grow normally. They may die or fail to grow, or blow over in the first good wind.

Rooting hormone: A powder containing growth hormones and sometimes certain vitamins. You dip the end of a cutting in rooting hormone before setting it in soil. The hormone stimulates root growth.

Single flower: Flowers with just a few petals are single (depending on their family the number varies). A single rose has five petals, a single poppy has four.

Sphagnum: A moss with long fibers sold dry for various garden uses. Use it for lining wire fern baskets, for air layering, or in chopped form as a soil conditioner. Much of the peat moss sold by nurseries contains sphagnum.

Standard: A plant that would normally grow as a bush with many branches, but has been trained by pinching and pruning to a single trunk. Roses are frequently grafted and trained as standards, and you may see azaleas, geraniums, or any other plant that is woody enough to support itself on a single stem.

Stolon: A stem that creeps along the surface of the ground, taking root at intervals and forming new plants where it roots. Another word for stolon is runner. Bermuda grass and strawberries form stolons.

Sucker: An unwanted shoot, often vigorous, that sprouts from the roots, base, stem, or even the main branches of a plant. Suckers often grow from rootstocks that have been grafted to a desired but weak-rooted plant. These are usually obvious because of a difference in foliage.

Taproot: Roots resembling carrots. Some plants that produce them are dandelions and oak trees. They often grow very deeply into the soil if there is a lack of water near the surface.

Tender: The opposite of hardy. That is, sensitive to cold weather.

Thinning out: In pruning, the term means removing entire branches, either large or small ones, to make a plant or tree less dense. In speaking of seedlings or young plants, thinning out means removing enough plants so that those remaining have room to spread leaves and roots.

Tuber: A swollen underground stem from which certain plants sprout.