A Glossary of Gardening Terms

One of the joys of gardening is to be well versed in the diversity of techniques and solutions to choose from. The first step to knowing them is to understand the terms associated with gardening practices.

Acidic: A soil, compost, or liquid with a pH between 0 and 7.0 (on a scale of 0.0-14.0). Often referred to as sour soil by gardeners.

Aeration: Any method of loosening soil or compost to allow air to circulate.

Aerobic: Describes organisms living or occurring only when oxygen is present.

Alkaline: A soil with a pH between 7.0 and 14 (on a scale of 0.0-14.0). Often referred to as “sweet” soil by gardeners.

Anaerobic: Describes organisms living or occurring where there is no oxygen.

Annual: A plant that blooms, produces seed, and dies in one year.

Bareroot: These plants have been field-grown and are supplied in a dormant state with the soil removed.

Beneficial Insect: An insect that benefits your garden by eating or laying its eggs in other insects, thereby controlling their population.

Biennial: A plant that completes its full life-cycle in two growing seasons. It produces leaves in the first and flowers in the second.

Biodegradable: Able to decompose or break down through natural bacterial or fungal action. Substances made of organic matter are biodegradable.

Biological Pest Control: Using living organisms such as beneficial insects or parasites to destroy garden pests.

Bolt: A term used to describe a plant that has gone to seed prematurely.

Bone Meal: Finely ground fertilizer composed of white or light gray bone that adds phosphorus to the soil.

Budding: A form of grafting that joins a bud, rather than a cutting, to a rootstock. It is often used for roses and fruit trees.

Calcitic Limestone: A 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.

Chlorosis: A yellowing or blanching of the leaves due to lack of chlorophyll, nutrient deficiencies or disease.

Clay Soil – Soil composed of many tiny plate-like soil particles that can compact with time to form a hard, solid mass that makes digging holes more laborious, and often results in poor drainage.

Cloche: Structure made of glass, plastic or horticultural fleece placed over a plant for protection or for forcing early crops.

Clone: One of several identical plants obtained from a parent plant by vegetative propagation.

Clump Forming: Plants that form clumps of foliage, often spreading to form other clumps close by.

Container Plant Style – Plants used in combinations are sometimes classified as thrillers, fillers, and spillers to identify what role each plant fulfills in a combination design.

Cordon: A plant carefully trained to grow as one main stem, or occasionally two or three main stems, by removing side-shoots

Corm: A rounded underground storage organ, consisting of the stem base, and often with a fibrous outer layer. It is replaced by the plant annually.

Crown: The growing point of a plant from which new shoots emerge, at or just below the soil surface.

Cultivar: A plant that is bred or selected by growers for unique flowers, leaf color, growing habit etc. It has distinct and uniform characteristics that differ from the original species.

Companion Planting: The sowing of seeds in the garden in such a way that plants help each other grow instead of competing against each other.

Compost: Completely decayed organic matter used for conditioning soil. It is dark, odorless and rich in nutrients.

Cover Crop: Vegetation grown to protect and build the soil during an interval when the area would otherwise lie fallow.

Crop Rotation: The planting of a specific crop in a site different from the previous year.

Cutting: A vegetative method of plant propagation whereby a piece of plant leaf, stem, root or bud is cut from a parent plant. It is then inserted into a growing medium to form roots, thus developing a new plant.

Damping Off: Decay of young seedlings at ground level following fungal attack. Often the result of soil borne diseases and over watering.

Dead Heading: The act of removing spent flowers or flowerheads for aesthetics, to prolong bloom for up to several weeks or promote re-bloom, or to prevent seeding.

Deep Shade: A plant requiring less than 2 hours of dappled sun a day.

Desiccate: Cause to dry up. Insecticidal soap desiccates its victims.

Dibber: A stick for making holes for seedlings to be transplanted.

Disbudding: Removing surplus buds or shoots so that those remaining grow larger or stronger.

Dot plant: A plant grown singly or well spaced in a bed to emphasize a feature such as colour, height or texture.

Direct Seed: To seed directly into the soil instead of starting your seeds indoors.

Double Digging: A method of preparing the soil by digging a trench then putting the soil from one row into the next row.

Drought Resistant – Plants that can withstand periods with little to no supplemental water when planted and established in the landscape.  No plant in a pot is truly drought resistant as they all need some water.  All plants will need to be watered while getting established.

Espalier: A tree with branches trained to grow horizontally, in tiers, about 37cm (15 in) apart.

Exposure – the optimum amount of sun or shade each plant needs to thrive

  Full Sun – 6 or more hours of direct sun a day

Partial Sun or Partial Shade – 4 to 6 hours of direct sun a day

Full Shade – less than 4 hours of direct sun a day

Dappled Shade – areas where there is a mixture of sun and shade,

Feathered Maiden: A one-year old tree with several side branches (feathers).

Fertilizer: An organic or synthetic material added to the soil or the plant that is needed to increase its nutrient value.

Foliar Fertilizing: A technique of feeding plants by applying liquid fertilizer directly to plant leaves.

Frost Date: This is the average expected last frost date for your area. Frost dates are important to know for your gardening zone or planting area.

Fungicides: Compounds used to prevent the spread of fungi in gardens and crops, which can cause serious damage to plants.

Germinate: The beginning of growth in seeds, the action of sprouting, budding or shooting, above the soil. This occurs whenever a plant or seed begins to vegetate into leafy young plants.

Green Manure: A crop 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.

Hardening Off: The process of acclimatizing plants grown under protection, in the greenhouse for example, to cooler conditions outdoors.

Head-space: Space left between the top of the soil and the top of the container.

Heavy Soil: A soil that contains a high proportion of clay and is poorly drained.

Height, Medium – Plants that are between 10 and 24 inches in height.  These plants are often used in the center (or between the tall and short plants) in a mixed bed or as filler in a container.

Height, Short – Plants that are 10 inches or less in height.  These plants are often used in the front of mixed beds or the edges of pots.

Height, Tall – Plants that are 24 inches or more in height.  These plants are often used at the back of mixed beds or in the center of containers.

Humus: A fairly stable, complex group of nutrient-storing molecules created by microbes and other forces of decomposition by the conversion of organic matter. Typically its dark loamy earth.

Hybrid: A crossbreed between two different species.  Seeds taken from hybrids will not produce fruit that is true to the parents.  Instead, they tend to revert to a form of the grandparent fruit

Integrated Pest Management (IPM): A pest control strategy that uses an array of complementary methods: natural predators and parasites, pest-resistant varieties, cultural practices, biological controls, various physical techniques, and pesticides as a last resort.

In situ: A plant placed in its permanent growing position.

Layering: This is an easy propagation method that forces a shoot to produce roots while it is still attached to the parent plant.

Loam: Soil that contains clay and sand

Microclimate: A small area with a different climate than the surrounding area

Micro-Nutrients: Some mineral elements are needed by plants in very small quantities. If the plants you are growing require specific “trace elements” and they are not getting them through the soil, they must be added.

Mulch: Any organic material, such as wood chips, grass clippings, compost, straw, or leaves that is spread over the soil surface (around plants) to hold in moisture and help control weeds.

No-Till-Gardening: This type of gardening calls for no cultivation (or tilling) of the soil after the initial tilling. In its place, regular mulches are added and plants are planted through the mulch.

N-P-K: An abbreviation for the three main nutrients that have been identified as absolutely necessary for plants are nitrogen (N), phosphorus (P) and potassium (K). These three are also known as “macronutrients,” and are the source of the three numbers commonly found on fertilizer labels.

Organic: Refers to something derived from living organisms and is made up of carbon-based compounds. It is also a general term used for a type of gardening using no chemical or synthetic fertilizers or pesticides.

Organic Gardening: This method of gardening is based on building a healthy, living soil through composting and using supplemental nutrients from naturally occurring deposits. The basic principle is to feed the soil so the soil will feed the plants. Healthy plants are better able to resist pests and disease thus reducing the need for control.

Peat moss: Peat made from sphagnum moss

Perennial: A plant that grows and flowers for years. They are either evergreens or may die back to the ground but will grow again the following season.

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.

Pinching out: Removing the growing points of a young plant to encourage side-shoots to form. This encourages a bushy habit and more flowering stems.

Pollination: The transfer of pollen between flowers, which can be carried out by the wind, insects, animals or by hand.

Rhizome: A fleshy underground stem or runner. Creeping grasses spread by rhizomes.

Rootstock: The underground part of a plant containing the roots. In grafting, a plant (scion) is joined to a desirable rootstock – often to promote a dwarfing habit.

Rootball: the roots and accompanying soil when a plant is removed from a container or lifted from the ground

Slow Release Fertilizer: Fertilizer that comes in pellets and is slowly released based largely on microbes which are more or less active based on soil temperatures.

Soil Amendment: Material added to the soil to improve its properties. This may include; water retention, permeability, water infiltration, drainage, aeration and structure. Soil amendments are mostly organic matter or very slow release minerals and are typically worked into the topsoil.

Soil Test: A measurement of the major nutrients (nitrogen, phosphorous, and potassium) and pH levels in the soil.

Standard: A tree or shrub that has been trained to a certain height with a long bare stem and foliage at the top

Taxonomist: A scientist whose job it is to classify plants, or other organisms, into their correct Scientific classifications.

Thriller – Plants that are placed in the center or back of a combination planter to add drama and height to the combination.

Tilth: Describes the general health of the soil including a balance of nutrients, water, and air. Soil that is healthy and has good physical qualities is in good tilth.

Time Release Fertilizer: Also called Controlled Release Fertilizer.  Fertilizer comes in pellets and is an improved version of Slow Release Fertilizer.  Fertilizer is released based on soil temperature itself (not microbe action) and tends to be more exact than Slow Release Fertilizer.

Topdressing: Applying fertilizers or some kind of soil amendment after seeding, transplanting or once the crop has been established.

Topsoil:  the upper layer of soil that you plant in.  It varies in depth from place to place, but will almost always be less than a foot deep and can be as little as 2 inches deep

Trace Elements: Nutrients that plants need in small amounts.  Common trace elements include Boron, Copper, Iron, Manganese, Molybdenum, and Zinc.  These elements are usually included in most commercial fertilizers.

Trailing – Plants that trail along the ground or out of pots but do not root at nodes along the stem.

Transplanting: The moving of a plant from one growth medium to another.

True Leaves: When the seedlings first emerge, they have a set of small leaves.  The next set of leaves that grow are usually considered the “true leaves.”

Variegated Foliage – Foliage with different colors, usually but not always random, alternating on the foliage.

Vermicomposting: The use of red worms to convert food scraps or other organic materials into worm castings.

Water Soluble Fertilizer – Fertilizer that either comes in liquid form or comes in crystal form that is dissolved in water.

Wet Feet – When the soil in a container or the landscape stays wet, plants may be referred to as having wet feet.

Worm Casting: The digested organic waste of red worms. Gardeners consider them the most nutrient dense organic compost available.

Xeriscaping: To create a low maintenance landscape with native plants and small or non-existent areas of turf grass. One of the primary goals of xeriscaping is to reduce landscape water use.