Raised Bed Gardening Basics
Raised beds make it easier to organise crops, protect soil from compaction and garden comfortably in small spaces or on difficult ground. They are not essential for every garden, but a well-planned bed can improve drainage, extend the growing season slightly and simplify maintenance.
Choose a sunny site with convenient access to water, especially for vegetables, herbs and cut flowers. Watch the area at different times of day before building, as fences and trees can cast more shade than expected. Leave enough room around each bed for a wheelbarrow, watering can and comfortable movement. A bed about 1 to 1.2 m wide lets most people reach the centre from either side without stepping on the soil. Length is flexible and should suit your space. Keep the height modest unless access needs make a taller bed helpful. Check for underground services before driving stakes or digging deeply near a house or boundary.
Use durable, untreated materials where possible, such as naturally long-lasting timber, recycled plastic boards, brick or stone. Avoid materials that may leach unwanted substances into food-growing soil. Build the sides level and secure, with corners firmly fixed so the bed can hold its fill. If you are placing it over grass or weeds, remove tough perennial roots first or cover the ground with plain cardboard. Soak the cardboard before filling so it settles closely to the soil. Do not line the base with impermeable plastic, as this can trap water and interfere with drainage. A fine mesh base may be useful where burrowing pests are a known problem.
Fill the bed with a blend suited to its depth and purpose. For a deeper bed, use good-quality topsoil mixed with mature garden compost or well-rotted manure. In a shallow bed, concentrate on improving the existing soil beneath and add compost on top. Avoid filling an entire large bed with bagged multipurpose compost, which can be costly, settle quickly and may not provide a stable long-term growing medium. Choose peat-free materials where possible. Break up large clods, remove obvious stones and level the surface without compacting it. Leave a few centimetres below the rim for mulch and watering, as the contents will settle during the first year.
Plan crops so that taller plants do not shade shorter ones, and group plants with similar watering needs. For an easy start, grow salad leaves, beetroot, spring onions, bush beans, chard or herbs that suit the season. Avoid overcrowding merely because the bed looks tidy when newly planted; good spacing improves airflow and makes watering easier. Mark what you sow with durable labels, particularly if several crops look similar as seedlings. Succession sowing small amounts every two or three weeks can provide a steadier harvest than sowing everything at once. Rotate crop families between beds or sections each year where practical, especially for frequently grown vegetables.
Water raised beds more often than ground-level beds, because their exposed sides can dry out quickly. Check the soil a few centimetres below the surface before watering, then water thoroughly around the roots when needed. Use stored water from a water butt where suitable, and mulch the surface with garden compost, leaf mould or chopped leaves to reduce evaporation. Keep the soil covered between crops with mulch or a green manure. Add a 3 to 5 cm layer of compost or well-rotted manure each year to replace organic matter used by crops. Avoid standing or kneeling on the bed, as its loose structure is one of its main advantages.
Maintain the frame and soil a little at a time. Inspect wooden sides each spring for loose fixings or rot, and top up settled soil before the main growing season. Weed early, while seedlings are small, and remove diseased plant material promptly rather than adding it to compost if you are uncertain about it. If one crop performs poorly, investigate drainage, shade, watering and soil condition before adding more fertiliser. Raised beds make it easier to test and improve one small area at a time. With annual compost, sensible crop rotation and clear paths, a raised bed can stay productive for many years without needing to be emptied and rebuilt.
Frequently asked questions
How deep should a raised bed be?
For many vegetables, 20 to 30 cm above workable ground is enough, because roots can continue into the soil below. Choose a deeper bed if the soil beneath is very compacted, poorly drained or inaccessible, or if you need greater height for comfortable gardening. Depth matters less than good soil and drainage.
Do raised beds need a base?
Usually no. Leaving the base open connects the bed to the underlying soil and allows drainage, roots and worms to move through. Put cardboard over grass after removing persistent roots if needed. Use a fine mesh base only where burrowing pests are a specific and recurring problem.
What is the best soil mix for a raised bed?
Use a stable blend of good topsoil with mature garden compost or well-rotted manure, then improve it annually with a surface compost mulch. The best balance varies with local soil and bed depth. Avoid relying entirely on bagged multipurpose compost, and choose peat-free materials wherever possible.
General guidance for UK home gardens and allotments. Conditions vary by region, soil and season; the RHS or a local garden centre can give site-specific advice. Page updated 19 Sep 2026.