Use this A–Z list to decode words found in tenancy notes, seed packets and Tilthwick's allotment guides. Each term heading has its own link, so you can bookmark or share a definition.
Allotment
A piece of land rented for growing fruit, vegetables, flowers or other plants. In the UK, a council, association or private landlord may manage the site. See how to get an allotment.
Annual weed
A weed that completes its life cycle in one year. Annual weeds can go into a well-managed compost heap before they set seed. See clearing an overgrown allotment.
Brassica
A crop in the cabbage family, including cabbages, kale, cauliflower and Brussels sprouts. Brassicas are commonly treated as one group in a crop rotation.
Brown material
Dry, carbon-rich compost ingredients such as chopped woody prunings, dead stems, straw, shredded paper and plain cardboard. Mix browns with green material rather than adding one type alone. See allotment compost bays.
Clay soil
Soil with a high proportion of very small mineral particles. It can hold water and nutrients well but may drain slowly; adding organic matter can improve its structure.
Cloche
A low, usually transparent cover placed over plants. It gives shelter and some extra warmth and can help protect young plants.
Companion planting
Growing different plants together in the hope that one benefits another, for example by attracting wildlife or confusing a pest. Treat it as one part of plot planning, not a replacement for sound crop care.
Compost
Decomposed plant material used as a soil improver or mulch. Garden compost is different from the bagged seed or potting compost used to raise plants in containers. See allotment compost bays.
Compost bay
A large, contained space for composting, often made from timber or pallets. Several bays let you keep fresh material, maturing compost and ready compost apart.
Crop rotation
Moving crop groups to a different bed in later seasons. It helps reduce the build-up of soil-borne problems linked with particular crops. See the allotment crop rotation guide.
Dip tank
A shared tank from which plot holders fill watering cans. Follow the site's rules and do not contaminate the stored water.
Fleece
A light horticultural fabric laid over or supported above crops. It can shelter young plants from cold and wind and exclude some pests.
Fruit cage
A framework covered with suitable netting to keep birds away from soft fruit. Install and maintain netting so wildlife cannot become trapped. See fruit cages and netting.
Green material
Soft, nitrogen-rich compost ingredients such as grass clippings, leafy crop waste, annual weeds and vegetable peelings. Mix greens with brown material for a better-aerated heap.
Green manure
A fast-growing crop sown mainly to cover and protect bare soil. It is cut down or incorporated before the ground is needed for the next crop.
Intercropping
Growing a quick crop in the gaps around a slower, widely spaced crop, then harvesting it before the main crop needs the space.
Lease
The agreement that sets out how an allotment site or plot may be used. Read it alongside the site rules before putting up a shed, greenhouse or polytunnel. See allotment tenancy questions.
Mulch
A layer laid on the soil surface to cover it. Organic mulches such as well-rotted compost can add organic matter, reduce evaporation and suppress some weeds.
No-dig
A way of growing that avoids routinely turning over the soil. Beds are covered with organic matter and crops are planted into the surface layer. See no-dig allotments.
Organic matter
Material from living or once-living things, such as well-rotted garden compost or manure, added to support soil structure and water management.
Perennial weed
A weed that lives for more than one year and can regrow from roots or underground stems. Bindweed and couch grass are common examples on allotments.
pH
A number describing how acid or alkaline soil is. A value of 7 is neutral; values below 7 are acid and values above 7 are alkaline.
Raised bed
A growing area with its soil surface above the surrounding ground, usually contained by edging. Raised beds can help access and drainage but are not compulsory. See allotment raised beds.
Rod
A traditional unit used when describing allotment size. The RHS describes a full plot as 10 rods, approximately 250 square metres; modern sites also offer smaller plots. See allotment plot sizes.
Sandy soil
Soil with a high proportion of larger mineral particles. It usually drains freely and can dry quickly; organic matter can help it retain moisture.
Seedling
A young plant grown from seed. Seedlings are vulnerable to drying out, cold and feeding damage while they establish.
Standpipe
A fixed outdoor water point shared by plot holders. Site rules may restrict attaching hoses or leaving water running.
Successional sowing
Sowing a smaller amount of the same crop at intervals so it matures over a longer period rather than all at once.
Tilth
The condition and texture of prepared surface soil. A fine, crumbly tilth is used for small seeds so they have close contact with moist soil.
Water butt
A container that stores rainwater, usually collected from a shed or greenhouse roof. Use fresh tap water rather than stored rainwater for seedlings because stored water may contain pathogens. See watering an allotment.
Weed-suppressing membrane
An opaque sheet used to cover soil and reduce weed growth while an area is not being cultivated. Check site rules, secure it well and remove it when it is no longer needed.
Sources
- RHS: Choosing, clearing and beginning work on an allotment checked 14 Nov 2026
- RHS: Practical layout, watering, paths, crop rotation and crop protection on allotments checked 14 Nov 2026
- RHS: When and how to water vegetables, seedlings and container crops checked 14 Nov 2026
- RHS: RHS no-dig: a new bed can be planted once made when its organic mulch is well rotted and sufficiently deep; minimise traffic on saturated beds and use planks to spread weight when needed awaiting check
- RHS: Making and using garden compost on a plot checked 14 Nov 2026
- RHS: Understanding and testing garden soil pH checked 14 Nov 2026