Glossary of Gardening

Glossary of Gardening Terms: Q to Z

We realise it can get a little confusing sometimes trying to decipher grow guide instructions, botanical research papers and other publications relying heavily on horticultural terminology, so here’s the final part of our A-Z glossary of gardening terms.

An A-Z Glossary of Gardening: A to C | D to H | I to P | Q to Z


An A-Z Glossary of Gardening: Q to Z

Gardening Glossary – R

Rejuvenate – To restore youth. Mature plants which have completed their life cycle can often be rejuvenated (therefore producing new growth) by altering their photo-period.

Rhizome – A plant’s fleshy underground runner or stem. For example, Phalaris are rhizomatous grass species.

Root bound – Referring to roots inhibited from normal growth due to being grown in an insufficiently spacious container.

Rootball – Refers to the combination of roots and the soil accompanying them when the plant is lifted from its container or the ground.

Roots – The underground part of a plant, which variously anchors, feeds and hydrates it.

Rosette – A cluster of leaves which radiates the same approximate point – often at ground level.

Gardening Glossary – S

Salt – A crystalline compound which can burn plants and so cause problems with nutrient absorption, salts result from fertiliser build up or an unsuitable pH level.

Season extender – Referring to equipment or techniques used to extend a spring or autumn growing season, such as cold frames, greenhouses, hotbeds, etc.

Secondary nutrients – Referring to calcium (Ca) and magnesium (Mg).

Seed pod – A plant’s dry calyx, containing one or more seeds (either maturing or mature).

Seedling – Referring to the young plant initially developing from a seed.

Soil amendment – Usually slow-release minerals or organic matter, typically turned in to the topsoil layer to improve properties such as aeration, drainage and water retention.

Soil test – The measurement of a soil’s major nutrients (nitrogen, phosphorous and potassium) and pH levels.

Soluble – Referring to a substance that can be dissolved in water.

Spore – A fungal spore is roughly equivalent to a plant’s seed.

Sprout – Referring to either young leaf or stem growth or a freshly germinated seed.

Square feet – A measurement resulting from the multiplication of an area’s length by its width in feet.

Stamen – A male plant’s pollen-producing organ.

Starch – A complex carbohydrate which is made and stored in food.

Sterilise – To destroy any and all bacteria, dirt and germs present in a given area, making it sterile.

Stomata – The tiny pores on the underside of leaves which is responsible for transpiration and other essential functions.

Stress – Chemical or physical factors which causes extra exertion by plants, usually negatively affecting its growth and overall health.

Sugar – Carbohydrates which contain a chain of hydrocarbons, used by plants as nourishment.

Synthesis – The production of a substance (e.g. chlorophyll) by the combination of light energy and chemical compounds or elements.

Systemic weed killer – A weed killer applied to leaves, for absorption and distribution throughout the plant.

Gardening Glossary – T

Tap root – A plant’s main or primary root. Initially growing from the seed, the tap root will then branch off into lateral roots.

Total Dissolved Solids – Referring to the total amount of dissolved solids in a solution.

Tepid – Warm water (~21°C to 27°C) should be used to both facilitate a plant’s chemical processes and to reduce the risk of shocking it.

Terminal bud – The bud at the growing tip of a plant’s primary stem.

Thin – To cull out weak or slow-growing seedlings by weeding.

Tilth – A fine, crumbly layer on the surface of soil; Soil that is “in good tilth” contains a healthy balance of air, nutrients and water.

Topdressing – The application of fertiliser or other additives subsequent to seeding or transplanting.

Transpire – The process where plants exude water vapour and by-products via their stomata, taking in CO2 via their leaves.

Transplanting – Moving a plant from one growing medium to another.

Trellis – A frame or netting used to training or supporting plants (for example, Passiflora species).

Triecious – Referring to the occurrence of male, female and hermaphrodite flowers on different plants of the same species.

Gardening Glossary – U

Ultraviolet – Non-visible light with very short wavelengths.

Gardening Glossary – V

Variety – A distinct phenotype or strain of a particular species.

Vent – To open a door, window or flap, etc., to encourage the circulation of fresh air.

Ventilation – Essential to any healthy indoor garden, this refers to the circulation of fresh air.

Vermicomposting – Using red worms to convert food scraps or other organic matter into useful worm castings.

Gardening Glossary – W

Wetting agent – Compounds used to lower the surface tension of water, making it wetter.

Wick – Used as part of a passive hydroponic system. A wick suspended in nutrient solution allows the solution to pass along it to be growing medium and the plant’s roots.

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

Gardening Glossary – X

Xeriscaping – A low-maintenance gardening practice which can be used to minimise water requirements, making use of native plants in combination with small or non-existent areas of turf grass.


An A-Z Glossary of Gardening: A to C | D to H | I to P | Q to Z