Glossary of Garden Terms

pressing lavender flowers in book By darkhriss AdobeStock Gardeners have their own vocabulary. Some of the terms are familiar, others less so, and a few seem to have a different meaning when used in a context outside of gardening.

Here is a glossary of terms you may come across while gardening.

Garden Terms

Balanced fertilizer: a fertilizer that has a fertilizer analysis with equal numbers (i.e. 10-10-10). See also Fertilizer.
Balled and burlapped (B&B): a method of transplanting trees and shrubs where the root ball is dug up with the soil intact and then wrapped in burlap to protect the roots and soil during transport and planting. See also Bare root, Containerized.
Bare root: plants, typically roses, trees, and shrubs, which have had all of the soil removed from their roots and are sold without soil or containers. See also Balled and burlapped (B&B), Containerized.
Bedding plant: plants, typically annuals, suitable for growing in beds and containers; quick, colorful flowers. See also Annual.
Beneficial insect: an insect that benefits your garden by feeding on or laying its eggs in other insects, thereby controlling their population.
Biennial: a plant that completes its full life cycle in two growing seasons (typically germination and growth the first year; flowering, seed production, and death the second year). In the garden, biennials left to reseed behave much like perennials. See also Annual, Perennial.
Biodegradable: able to decompose or break down through natural bacterial or fungal action.
Biological control: using living organisms such as beneficial insects or parasites to kill garden pests.
Bipinnate leaf: compound leaf structures with a feather-like formation of leaflets arranged in pairs, with each leaflet also pinnately divided into pairs (example: Kentucky coffeetree). See also Compound leaf.
Bolting: plants, typically vegetables, that begin to flower and set seed prematurely, reducing yield, making them bitter, or otherwise lessening their quality. Usually caused by late planting and temperatures that are too warm.
Bone meal: finely ground fertilizer composed of white or light gray bone that adds phosphorus to the soil. See also Fertilizer.
Bonsai: the art of growing carefully trained plants, typically trees, in small containers keeping the plants dwarf.
Botanical name: see Scientific name.
Bract: modified petal-like leaves, usually growing just below a flower or inflorescence (flower cluster). Often confused with petals or the flower itself (example: poinsettia).
Breaking bud: the stage of growth when a bud begins to grow and bursts through the protective bud scales.
Broadcast: spreading seeds (sometimes fertilizers) evenly over a large area, such as with grass seed, rather than in rows or hills.
Bud: an undeveloped shoot, leaf, or flower, or a combination of leaves and flowers forming on the sides or ends of shoots and in the angle formed where a leaf is attached to a shoot.
Bud scale scars: a ring of small ridges on a branch marking the start of a season’s growth.
Bulb: a thickened underground storage organ comprised of fleshy leaves (scales or layers) attached to a short, thick stem with basal roots (example: onion, lily). See also Corm, Geophyte, Tuber.
Bulb, tunicate: see Tunicate bulb.
Bulb, scaly: see Scaly bulb.

Caliper: the diameter of a trunk. Measured 6 inches off the ground for small trees, and 12 inches off the ground once the caliper reaches 4 inches.
Cambium: the thin membrane of living tissue located just beneath the bark of most garden plants and is responsible for the movement of water and nutrients in the plant.
Capitulum: an inflorescence that resembles a single flower but is made of many smaller flowers, typically a cluster of flowers with no petals in the middle (called disc flowers) surrounded by a ring of small showy flowers (called ray flowers); flower type for the aster family (example: daisy). Also called composite flower, flower head. See also Inflorescence.
Catkin: a slender, spikelike, drooping flower cluster (example: birch). See also Inflorescence.
Chelate: used in fertilizers to keep nutrient metals, such as iron, mobile in the soil and thus available to plants rather than locked up in insoluble mineral salts. They are comprised of complex organic compounds that enclose the plant nutrient.
Chimera: a nongrafted organism (plant) composed of two or more genetically different tissues.
Chlorosis: yellowing plant tissue, such as leaves.
Clay: a small soil particle with a diameter of less than 0.002 mm. Because they are so small, soils high in clay tend to have poor water and air penetration. See also Sand, Silt.
Cloche: a small translucent cover placed over plants to protect them from insect or frost damage. Traditionally it is bell-shaped.
Coir: the fiber from the outer husk of the coconut used in potting soil or to line hanging baskets. Also called coconut coir, coconut moss. See also Potting soil.
Cold frame: an unheated enclosure with clear covers that acts much like a small greenhouse used to protect plants and extend the growing season.
Common name: a familiar name used in certain circles or geographical regions to describe a plant. They are typically in the native language of the region. Because different plants can share the same common name and one plant can have several, their use can be confusing.
Companion planting: planting specific plants together so they benefit each other, rather than compete. Benefits may be attracting pollinators, serving as a trap crop, or acting as a living trellis.
Complete fertilizer: a fertilizer that contains an appropriate balance of all the nutrients necessary for plant growth. See also Fertilizer.
Complete flower: a flower that contains all four major components; sepals, petals, stamens, pistil. Also called a perfect flower. See also Incomplete flower.
Composite flower: see Capitulum.
Compost: an organic soil amendment resulting from the decomposition of organic matter. It is dark and odorless with the texture and appearance of soil. See also Humus.
Compound leaf: a single leaf where the leaf blade is divided into several discrete parts called leaflets. See also Simple leaf.
Cone: the reproductive structure of a conifer (gymnosperm).
Conifer: a cone-bearing plant typically with tiny needle or scale-shaped leaves. These types of plants do not form flowers, but instead have cones for pollination and seed production. While many conifers are evergreen, the terms are not synonymous. Not all conifers are evergreen and not all evergreens are conifers.
Containerized: plants growing in a container. See also Balled and burrlapped (B&B), Bare root.
Cool-season annual: annual plants that prefer cool temperatures, growing best in spring or fall. Many are tolerant of light frost (example: pansy).
Cool-season turfgrass: turfgrass species that prefer cool temperatures growing best between 60 and 75°F. They are green in spring and fall and dormant (brown) in summer (example: Kentucky bluegrass). See also Warm-season turfgrass.
Corm: a thickened underground stem that produces roots, leaves, and flowers during the growing season. See also Bulb, Geophyte, Tuber.
Corymb: a flat-topped or rounded cluster of flowers where the outer flowers have longer pedicels than the inner ones and blooms from the outside in. (example: candytuft). See also Inflorescence.
Cover Crop: vegetation grown in the absence of the normal crop to benefit the soil health. Used when the area would otherwise lie fallow.
Crop Rotation: the planting of a specific crop in a site different from the previous year.
Cross-pollination: the pollination of a flower with pollen from another flower or plant. See also Pollination, Self-pollination.
Crown: the transition area where a plant's roots and shoots join, usually at the soil level. Can also refer to the branched (upper) portion of a tree.
Cultivar: a cultivated variety of plant; a plant whose unique characteristics were developed by a horticulturist, not found in nature. See also Variety.
Cultivate: the process of breaking or loosening the soil surface by hand or with equipment (such as a plow or tiller) to prepare for planting. Cultivate can also refer to the process of removing weeds from a garden area.
Cutting: a method of propagation using vegetative sections of the plant (often stem tips) that are removed from the parent plant and placed in a growing medium to grow into a complete plant. See also Vegetative propagation.
Cyme: a flat-topped or rounded cluster of flowers where the outer flowers have longer pedicels than the inner ones and blooms from the inside out. (example: annual geranium). See also Inflorescence.

Damping off: the decay and sudden collapse of young seedlings at ground level following a fungal attack. Often the result of soil-borne diseases, poor air circulation, excessive humidity, and/or over-watering.
Deadhead: removal of spent, used, or dead flowers from a plant to improve appearance, promote repeat or prolonged bloom, and prevent self-sowing.
Deciduous: plants that shed all their leaves at one time at the end of the growing season and regrow them at the beginning of the next. See also Evergreen.
Deep shade: an area of the garden that receives less than 2 hours of dappled sun a day. Generally considered an extreme of full shade. See also Full shade, Part shade.
Desiccate: cause to dry up or dry out, often from winds or intense sunlight.
Determinate inflorescence: an Inflorescence that blooms from the top down or the inside out. Also called cymose. See also Indeterminate inflorescence.
Dibble: a small pointed tool used to make holes in the soil for seeds, bulbs, or young plants.
Dioecious plant: a plant that has male flowers on one plant and female flowers on another. In order to produce fruit and viable seeds, both a female and male plant must be present (example: ginkgo). See also Monoecious plant.
Direct sow: planting seeds directly into the garden rather than starting them in containers indoors and transplanting them outdoors later. Also called direct seed.
Disbud: the removal of side shoots and flower buds to leave only one main stem with one larger flower at the top.
Division: the separation or splitting of plants into two or more whole/entire pieces that contain all vegetative parts (roots, shoots, leaves, etc.). See also Vegetative propagation.
Dormancy: a period of slow growth or rest as part of the yearly cycle in a plant's life. Can be induced by shortening days, cool temperatures, or dry conditions.
Double digging: a method of preparing the soil by systematically digging an area to the depth of two shovels.
Double flower: a flower with more than the normal number of petals, which gives it a very full appearance. See also Single flower.
Drip line: the circle that would exist if you drew a line below the tips of the outermost branches of a tree or plant.

Fallow: land that has been prepared for cultivation or used for cultivation in the past, but lies unplanted or unused.
Fertilizer: an organic or synthetic material added to the soil or the plant that is important for its nutrient value, done to improve the quality or quantity of plant growth.
Fertilizer analysis: the three-number notation on a fertilizer container that indicates the percentage of the bag by weight of nitrogen, phosphate (which contains phosphorous), and potash (which contains potassium) (example: 10-6-4 contains 10% nitrogen, 6% phosphate, and 4% potash).
Fertilizer, balanced: see Balanced fertilizer.
Fertilizer, complete: see Complete fertilizer.
Flat: a shallow box or tray used to grow plants.
Floating row cover: a lightweight fabric spread or floated over a row of plants to extend the growing season by trapping heat during the day and releasing it at night. Also used as a barrier for insect pests.
Floricane: the second-year cane of a plant that flowers and fruits (example: raspberry). See also Primocane.
Floriculture: the cultivation and management of ornamental flowering and foliage plants, especially for florist shops.
Foliage: leaves.
Foliar feeding: applying liquid fertilizer directly to leaves rather than soil. Also called foliar fertilizing.
Forcing: the process of hastening a plant's growth to maturity or bloom, often out of season.
Freeze: occurs when the air and interior of the plant drop below 32°F. See also Frost.
Frond: the leaf of a fern or palm.
Frost: the formation of ice crystals on the surface of the leaf. See also Freeze.
Frost date: the average expected last killing frost in spring or the first killing frost in fall for your area.
Full shade: an area of the garden that receives less than 2 hours of direct sun a day. See also Deep shade, Part shade.
Full sun: an area of the garden that receives more than 6 hours of direct sun a day. See also Part sun
Fungicide: compounds used to prevent the spread of fungi on plants. See also Pesticide.

Hardiness: the ability of a plant to withstand low temperatures or frost without artificial protection.
Harden off: the process of gradually acclimatizing plants to different (usually harsher) growing conditions, such as from indoors to outdoors, to increase their resiliency.
Hardiness zone: a climatic region defined by the average lowest winter temperature. The USDA Plant Hardiness Zone map is the most used reference.
Hardpan: an impervious or poorly draining layer of soil (usually clay) beneath the topsoil.
Head: see Capitulum.
Heading back: cutting back a stem to a bud. See also Thinning out.
Heavy soil: a soil that contains a high proportion of clay and is poorly drained.
Heeling in: the process of temporarily covering a plant's roots with soil (sometimes mulch) to provide protection until it is ready to be permanently planted.
Heirloom: an old, open-pollinated variety of plant (typically vegetable) that has been passed down from generation to generation.
Herbaceous: not woody.
Herbicide: compounds used to kill plants (typically weeds). See also Pesticide.
Hill: a spot where several plants of the same kind are grown together as one group. Often soil is mounded up around the base of these plants.
Holdfast: a root-like structure that holds a vine to its support. See also Tendril.
Horticulture: the art and science of growing garden crops such as fruits, vegetables, trees, shrubs, and ornamental plants.
Honeydew: the sticky substance that is secreted by sucking insects such as aphids, scale, and mealybug. See also Sooty mold.
Humus: the dark, brown or black organic matter component of soil resulting from microbial action that breaks down organic matter. See also Compost, Green manure, Leaf mold, Organic matter.
Hybrid: the offspring of two plants of different species or varieties that have been deliberately cross-pollinated in order to acquire a new plant with desirable characteristics such as bloom color, disease resistance, fragrance, size, hardiness, taste, or shelf life, among others.
Hydroponics: the growing of plants in liquid solutions instead of in soil. See also Aquaponics.

Palmate: a compound leaf structure with segments radiating from a central point, like fingers (example: buckeye).
Panicle: a multi-branched cluster of flowers (example: lilac). See also Inflorescence.
Parasitic plant: a plant that lives on and acquires its nutrients from another plant.
Part Shade: an area of the garden that receives more than 2 hours, but less than 4 hours of direct sun a day. See also Deep shade, Full shade.
Part Sun: an area of the garden that receives more than 4 hours, but less than 6 hours of direct sun a day. See also Full sun.
Peat moss: the partially decomposed remains of various mosses and a typical component of potting soil. Good for providing water and nutrient retention and has an acidic pH. See also Potting soil.
Pedicel: the stalk of a single flower within an inflorescence.
Peduncle: the stalk of an inflorescence or solitary flower.
Perennial: plants with a lifecycle that is longer than two years. They usually bloom for one season each year and may die back to the ground over winter and return year after year, or remain evergreen throughout their lifespan. See also Annual, Biennial.
Perlite: a mineral, which, when expanded by a heating process, forms light granules. In potting soil, perlite provides good moisture retention while allowing good drainage. Also used for rooting cuttings. See also Potting soil.
Pest: any insect or animal which is detrimental to the health and well-being of garden plants.
Pesticide: a substance used to kill, prevent, reduce, destroy, or repel pest organisms harmful to cultivated plants. See also Fungicide, Herbicide, Insecticide, Miticide.
Petals: the modified leaf in a flower surrounding the stamen and pistil. Often large and colorful to help attract pollinators. One of the four major parts (whorls) of a flower: sepals, petals, stamens, and pistils.
Petiole: a leaf stalk.
pH: a scale from 0-14 that explains the degree of acidity or alkalinity of the water or soil. Soil pH is very important because it affects the availability of nutrients to plants and the activity of microorganisms in the soil. See also Acidic soil, Alkaline soil.
Photosynthesis: the internal process by which a plant turns sunlight into growing energy; the formation of carbohydrates in plants from water and carbon dioxide, by the action of sunlight on the chlorophyll within the leaves.
Phylloclade: a flattened stem that functions and often resembles a leaf (example: holiday cacti).
Pinching: removing small shoots and stems at the tip (usually with your thumb and index finger) to promote branching and a bushier, fuller plant.
Pinnate: a compound leaf structure with a feather-like formation of leaflets arranged in pairs or alternating along the main stem (example: honeylocust).
Pistil: the seed-bearing organ of a flower, consisting of the ovary, stigma, and style. One of the four major parts (whorls) of a flower: sepals, petals, stamens, and pistils.
Pistilate flower: a flower that contains pistils but no stamens. Also called a female flower, gynoecious. See also Dioecious plant, Incomplete flower, Monoecious plant.
Pollination: the transfer of pollen from the stamen to the pistil, which results in the formation of a seed often achieved by wind, insect, or other animal.
Pomology: the cultivation of fruits.
Potting soil: a soilless media made of various components designed for use in containers with larger particles and pore spaces that allow for greater aeration and drainage while providing good nutrient and water-holding capacity. Typical potting soil contains things like peat moss, sphagnum moss, coir, perlite, and vermiculite. Also called potting mix, potting media.
Primocane: the non-productive, non-flowering and fruiting first-year cane of a plant (example: raspberry). See also Floricane.
Propagation: creating more plants. See also Seed propagation, Vegetative propagation.
Propagation, Cutting: see Cutting.
Propagation, Division: see Division.
Propagation, Grafting: see Grafting.
Propagation, Layering: see Layering.
Propagation, Seed: see Seed propagation.
Propagation, Tissue culture: see Tissue culture.
Propagation, Vegetative: see Vegetative propagation.
Pruning: the cutting and trimming of plants to remove dead or injured wood or to control and direct the new growth of a plant.

Sand: the largest of soil particles with a diameter between 0.05 and 2.0 mm. Because they are larger, soils high in sand tend to have sharp drainage and dry out quicker. See also Clay, Silt.
Scaly bulb: bulbs without a papery covering (tunic). Also called nontunicate (Example: Lily). See also Tunicate bulb.
Scarification: scratching, cutting, nicking, or otherwise damaging a seed’s hard surface to allow water uptake and facilitate germination.
Scientific name: the universally accepted name assigned to a plant using the Latin-based terminology developed by the Swedish botanist Carolus Linnaeus in the 1700s. It is comprised of the genus and specific epithet. Using a plant’s scientific name eliminates the risk of confusing it with other plants. Also called a botanical name. See also Genus, Species, Specific epipthet.
Scion: a short length of stem taken from one plant which is then grafted onto the rootstock of another plant. See also Grafting.
Season extender: any technique or piece of equipment used to extend the growing season in both spring and fall. (example: cold frame, row covers).
Seed propagation: growing new plants from seed. Unlike vegetative propagation which creates clones, seed propagation produces hybrids or progeny that are similar but not genetically identical to the parent plants. See also Hybrid, Vegetative propagation.
Seed starting mix: a potting media well-suited for starting seedlings. See also Potting soil.
Seedling: a young plant that has developed from a seed.
Self-pollination: the transfer of pollen from the anther of a flower to the stigma of the same flower. See also Cross-pollination, Pollination.
Self-seeding: the spreading and growth of seeds by the plant through scattering or dropping them onto the surrounding soil. Also called self-sowing.
Sepals: the modified leaf in a flower surrounding the petals; protects the flowers as they emerge and may be large and colorful like petals. One of the four major parts (whorls) of a flower: sepals, petals, stamens, and pistils.
Shoot: the growth of a branch for one season.
Side dress: sprinkling a line of granular, powdered, or pelleted fertilizer (or other amendments) alongside a row of plants rather than incorporating it into the soil or planting hole.
Silt: a medium-sized soil particle with a diameter between 0.002 and 0.05 mm. Because of their size, soils high in silt have good water retention and fertility but tend to be prone to compaction and erosion. See also Clay, Sand.
Simple leaf: a leaf with one undivided blade (not broken into smaller pieces/leaflets). See also Compound leaf.
Single flower: a flower having only the minimum number of petals for that variety of plant. See also Double flower.
Soil Amendment: see Amendment.
Soil pH: see pH.
Soil test: a measurement of the major nutrients and pH levels in the soil.
Solitary flower: a flower that is not part of an inflorescence; a plant without clusters of flowers (example: tulip). See also Inflorescence.
Sooty mold: black fungus that grows on honeydew. See also Honeydew.
Sori: a cluster of sporangia on the fronds of ferns. Each species has a relatively unique color, shape, and placement of sori to aid with identification. See also Sporangia.
Spadix: an inflorescence type with small flowers clustered on a fleshy stem surrounded by a large bract; flower type for the aroid family (example: Jack-in-the-pulpit, peace lily). See also Inflorescence.
Species: a group of plants (or other organisms) that is made up of related individuals able to produce fertile offspring and is identified by its scientific name. See also Scientific name.
Specific epithet: the second part of the scientific name that distinguishes the species from others in the same genus. When written, the specific epithet name should be lowercase and italicized (or underlined if handwritten). See also Scientific name, Species.
Sphagnum moss: a bog moss which, unlike peat moss, is not composted but used living/fresh. May be a component of a potting media or used for lining hanging baskets and air layering. See also Potting soil.
Spike: a raceme with flowers that have no pedicels (stalks). See also Inflorescence.
Sporangia: the small capsules or enclosures on the underside of fern fronds in which spores are formed. See also Spore.
Spore: the reproductive cell structure of ferns, fungi, and mosses. Fern spores develop inside sporangia. These types of plants do not form flowers or produce seeds. See also Sporangia.
Staking: using a stake or other structure to physically support a plant to prevent flopping, excessive bending, or damage.
Stamen: the pollen-bearing organ of a flower, consisting of the filaments that support the pollen-producing anther. One of the four major parts (whorls) of a flower: sepals, petals, stamens, and pistils.
Staminate flower: a flower that contains stamens but no pistils. Also called a male flower, androecious. See also Dioecious plant, Incomplete flower, Monoecious plant.
Standard: a tree-like form of a trained plant (often a shrub) to create a single leaf-less trunk topped with a rounded crown of leaves and flowers created through pruning, disbudding, and/or grafting.
Stolon: a modified plant stem that grows horizontally above the surface of the soil with new growth emerging from different points of the stolon. (example: strawberries).
Stratification: the process of exposing seeds or bulbs to cold temperatures, typically in a refrigerator or freezer, for a specific length of time (often 12-16 weeks) to emulate the outdoor winter conditions and break dormancy allowing for successful germination/sprouting.
Sucker: an often fast-growing vertical stem originating from the base of the plant or the rootstock of a grafted plant. See also Water sprout.
Summer annual: annual plants that germinate in the spring or early summer, grow and flower through the summer months, set seed in late summer and early fall, and are killed by the frost in the fall. New seed germinates the following spring, continuing the cycle (example: crabgrass). See also Winter annual.
Systemic: a chemical (typically an insecticide or herbicide) that is absorbed and distributed throughout the plant to either kill insects feeding on the plant or to kill the plant itself.

Taproot: the main, thick root growing straight down from a plant (example: carrot). Not all plants have taproots.
Tender plants: plants that are not winter hardy; plants that die over winter; plants sensitive to cold temperatures.
Tendril: the twisting, clinging, slender growth on some vines that allows the plant to attach itself to a support or trellis. See also Holdfast.
Tepals: sepals and petals that look the same.
Thatch: the layer of dead stems and leaves that builds up under many lawn grasses.
Thinning: removing excess seedlings to allow sufficient room for the remaining plants to grow.
Thinning out: removing entire branches from a tree or shrub back to its point of origin. See also Heading back.
Tilth: the condition of the soil describing its balance of nutrients, water, and air. Soil that is healthy and has good physical qualities is in good tilth. Can also refer to the fine, crumbly surface layer of soil produced by cultivation perfect for sowing seed.
Tissue culture: a form of vegetative propagation where plant cells, tissues, or organs are grown in a sterile environment on a nutrient medium, allowing for the creation of new plants or plant parts from a small sample of plant material. Also called Micropropagation. See also Vegetative propagation.
Top dress: to evenly spread fertilizers or other soil amendments over the surface of the soil.
Topiary: a method of pruning and training plants into formal shapes.
Topsoil: the top layer of native soil. Can also refer to the good quality soil sold at nurseries and garden centers.
Trace elements: see Micronutrients.
Transpiration: the release of moisture through the leaves of a plant.
Transplanting: the process of digging up a plant and moving it to another location.
Trap crop: Plants strategically planted to attract pests away from a primary crop, acting as a sacrificial plant that pests will infest instead of the desired plants.
Tuber: an enlarged, fleshy, underground stem (example: dahlia). See also Bulb, Corm, Geophyte.
Tunicate bulb: bulbs surrounded by a paper covering (tunic) (example: onion, tulip). See also Scaly bulb.