How to Build Raised Garden Beds on a Budget

Raised beds are the cheat code for vegetable growing: better drainage, warmer soil, fewer weeds, no digging, and gardening at a height that doesn’t destroy your back. The only problem is the cost — buy cedar kits and premium topsoil and a couple of beds can easily hit £300. But here’s the thing: a raised bed is just a box that holds soil, and boxes can be built from all sorts of cheap or free materials.

Here’s how to build raised garden beds on a budget — the cheapest materials that actually last, the soil-filling tricks that halve the cost, and what to plant first for maximum smugness.

The cheapest materials that actually work

Scaffold boards are the budget king: used boards cost £5–10 each from reclamation yards, they’re 225mm deep (perfect bed height), pressure-treated for ground contact, and two boards high makes a deep bed. A 2.4×1.2m bed needs six boards — £30–60 in timber, plus screws. New pressure-treated sleepers are sturdier but pricier (£15–25 each); avoid old railway sleepers (creosote) for veg beds.

Free alternatives: pallets (check for the HT stamp — heat-treated, safe; avoid MB — methyl bromide), old fence panels, even straw bales (they compost down over a season while growing your veg — genius). Whatever you use, line the inside with permeable landscape fabric (£10 a roll) to hold soil in while letting water drain. Don’t use plastic sheeting — it traps water and rots the timber faster.

Scaffold boards: £5–10 each used — the best budget timber.
Pallets (HT stamp only) and straw bales: free options that work.
Line with landscape fabric, never plastic sheeting.

How to build raised garden beds on a budget: the build

The classic 2.4×1.2m bed: cut boards to length (or buy them cut), screw corners together with 75mm exterior screws — two per joint, pre-drilled to stop splitting. For beds over 2m long, add a central brace (a short vertical board screwed across the middle) to stop the sides bowing out under soil pressure. Level the ground first — a wobbly bed looks terrible and stresses the joints.

No power tools? Many timber merchants cut to length for £1–2 a cut, and you can assemble with a £15 drill-driver. The whole build takes an hour per bed once you’ve done one. Site them where they’ll get 6+ hours of sun, leave 60cm paths between beds (wheelbarrow width), and orient long beds north-south so plants don’t shade each other.

2.4×1.2m is the classic size — reachable from both sides.
Brace long beds centrally; pre-drill to stop splitting.
6+ hours of sun, 60cm paths, long axis north-south.

Filling them without spending a fortune

Filling is where budgets die: a 2.4×1.2×0.45m bed needs about 1,300 litres of soil — that’s £80–120 in bagged topsoil. The budget method is layering (hugelkultur-lite): bottom third with logs, branches and twigs (free from any tree surgeon or your own pruning), middle third with grass sods flipped upside-down, compost and shredded cardboard, top 20cm with proper topsoil or compost. The woody base rots down over 2–3 years, feeding the soil as it goes.

Source soil cheaply: local council compost (£3–5 a bag, often excellent), farm manure (often free if you collect — must be well-rotted for veg), and bulk bags of topsoil (£60–90 for 1,000 litres delivered — half the price of individual bags). Never fill entirely with manure or compost — veg needs the structure of real soil. Our guide to preparing garden soil covers getting the mix right.

Layer it: logs/branches at the bottom, compost in the middle, soil on top.
Bulk bags (£60–90/1,000L) beat individual bags by half.
Council compost and well-rotted manure: cheap or free, excellent quality.

What to grow first (maximum smugness, minimum skill)

Year one, grow the things that make you feel like a genius: potatoes (impossible to mess up, taste transformative), courgettes (one plant feeds a street), runner beans (vertical growing, huge yields), salad leaves (cut-and-come-again, saves £££ on bagged salad), and herbs (supermarket herb pots cost £1.25 and die; a £2 rosemary plant lives for years).

Avoid in year one: cauliflowers (fussy), celery (needs constant water), and anything that takes all season for one meal (looking at you, parsnips — grow them in year two when you’re hooked). Plant what you actually eat — there’s no point growing a perfect kohlrabi nobody wants. And succession-sow salad every 3 weeks from April to August for continuous harvests instead of one overwhelming glut.

Year-one winners: potatoes, courgettes, runner beans, salad, herbs.
Skip the fussy stuff (cauliflower, celery) until year two.
Succession-sow salad every 3 weeks for continuous harvests.

Making them last

Untreated timber in contact with soil lasts 3–5 years; pressure-treated lasts 7–10. Extend life by: lining with fabric (done at build), keeping soil slightly below the top edge (less moisture against the boards), and oiling the outside annually with linseed or a garden wood preservative (£10 a tin, 20 minutes per bed). When boards eventually rot, you replace individual boards, not the whole bed — another reason to screw, not nail.

Top up the soil level every spring — it settles 5–10cm a year as organic matter breaks down. A 5cm mulch of compost each spring feeds the soil, suppresses weeds and retains moisture: the single highest-value habit in vegetable growing. And rotate crops yearly (don’t grow potatoes in the same bed two years running) to prevent disease buildup. If you’re fencing the veg patch too, the best fence paint for UK weather will keep the whole area looking sharp.

Pressure-treated + lined + oiled yearly = 7–10 years per bed.
Top up settling soil each spring; mulch 5cm of compost.
Rotate crops yearly; screw joints (not nails) for easy board replacement.

A raised bed doesn’t need to cost £150. Scaffold boards, free logs for the base, bulk soil and council compost get you growing for under £80 a bed — and the first potato harvest, earthed up by your own hands, tastes like nothing from a supermarket ever will. Build one this weekend. You’ll build three more by spring. The RHS’s vegetable growing guides are the gold standard for what to plant and when.