Raised Bed Gardening for Beginners

Raised beds fix three of the biggest problems UK gardeners face: heavy clay, poor drainage and a short growing season. If clay is your main battle, see our guide on how to improve clay soil. The RHS raised bed guide is a handy read too. Lift the soil 30cm off the ground and you control what goes in, it drains better and it warms up sooner in spring.

You don’t need a big garden or a big budget. Even a small garden has room for one. A single 1.2m x 2.4m bed gives you plenty of salads, herbs and veg through summer. Beds work on patios, lawns and even on concrete. Here’s everything from building your first bed to picking your first crop. For more ideas, browse our growing guides.

Choosing the right size

The measurement that matters most is width. You need to reach the middle from either side without stepping on the soil. Treading on it squashes the soil and undoes all your good work.

Standard sizes

A 1.2m x 2.4m bed has a surprising amount of space. You could fit around a dozen tomato plants, dozens of lettuces, or a mix of salad, herbs and climbing beans. Classic companion planting pairs, like carrots with onions or marigolds with tomatoes, fit nicely in a raised bed.

How many beds?

One or two beds is a great start. You’ll learn what grows well for you, then add more. Four beds make a simple crop rotation easy.

Gardener’s tip: Run beds north to south so both sides get the same sun through the day. Put tall crops like climbing beans at the north end so they don’t shade smaller plants.

What to build your bed from

Timber

Softwood timber is the most popular choice. It’s affordable, easy to cut and looks warm and natural.

• Larch: naturally resists rot and weathers to a soft silver-grey. The posh option.
• Douglas fir: similar to larch and a little cheaper. Weathers to silver-brown.
• Pressure-treated softwood: tanalised pine. Lasts for years, and modern treatments are fine for growing veg. Great value.
• Scaffold boards: cheap and easy to find. They won’t last as long, so they’re good for a budget or temporary bed.

Avoid: old railway sleepers (they may contain creosote), pallet wood (you don’t know what it’s been treated with) and untreated pine (it rots quickly).

Two 150mm x 50mm boards stacked make a 30cm bed. Screw them to 50mm x 50mm corner posts, and drill pilot holes first so the wood doesn’t split.

Other materials

• Brick or block: permanent and handsome. Needs proper foundations. Costs more but lasts decades.
• Galvanised steel: modern looking and very long-lasting. Panels bolt together quickly. Warms up fast in spring, but can get hot in summer, so water more.
• Stone: dry stone or mortared. Beautiful but pricey and hard work. Suits cottage and traditional gardens.
• Recycled plastic boards: no upkeep and never rot. Less natural looking.

A new bed in pressure-treated timber. Two boards high gives you 30cm, plenty for most veg.

Filling your raised bed

The soil mix

The classic mix is half topsoil and half garden compost. That gives you:

• Enough food for a full growing season
• Soil that holds water without getting soggy
• A crumbly texture roots love

A 1.2m x 2.4m x 30cm bed needs about 860 litres of mix in total. Use bagged or bulk compost, or your own garden compost.

How to fill it

1. On grass, lay cardboard over the turf first. It smothers the grass and rots away.
2. Mix the topsoil and compost together before you fill. Don’t layer them.
3. Fill to just above the rim, as the soil will settle.
4. Water well and leave it to settle for a week before planting.

Cardboard on the bottom smothers the grass, then rots away. Fill slightly above the rim, as the mix settles over the first week or two.

Topping up each year

The soil level drops a few centimetres a year as the compost breaks down. Each spring, add 5cm of fresh compost. It feeds the soil and keeps the level up. After a few years you’ll have lovely dark, rich soil.

Warning: Don’t fill beds with builder’s sand, subsoil or pure compost. Builder’s sand packs down, subsoil has no goodness in it, and pure compost stays too wet and sinks a lot as it breaks down.

What to grow in raised beds

Almost any veg, herb or cut flower is happy in a raised bed. The warmer, better-drained soil opens up more options than open ground.

Best veg for raised beds

Quick crops (ready in 4-8 weeks):

• Lettuce and salad leaves
• Radishes
• Spring onions
• Baby spinach
• Rocket

Main crops (ready in 8-16 weeks):

• Tomatoes: cordon types tied to canes
• Potatoes: great in 45cm deep beds
• Courgettes: one plant in a corner, as they spread
• Climbing French beans up a wigwam of canes
• Beetroot
• Carrots, in 45cm deep beds
• Chard

Herbs:

• Basil, coriander, parsley, chives and dill
• Give herbs one end of a bed. They’re compact and you’ll use them all the time.

Companion planting in raised beds

A busy raised bed in midsummer, with lettuce and beetroot at the front and climbing beans on a wigwam behind.

Planting and spacing

In a raised bed you can plant closer together than in long rows, because the soil is so good. Less bare soil also means fewer weeds.

Planting in squares

Picture your bed as a grid of 30cm squares. Each square holds one crop at its own spacing:

Keep sowing

Sow quick crops like lettuce and radishes every 2-3 weeks from March to September. Our seed sowing calendar shows the best timing for each crop. As one batch finishes, the next is ready, so you avoid one big glut followed by nothing.

When peas and broad beans finish in early summer, replant straight away with beetroot, carrots, chard and salad leaves. Try not to leave a raised bed empty in the growing season.

When one crop comes out, sow the next straight into the gap. Little and often keeps the bed full without a glut.

Crop rotation

Move crop families round your beds each year to keep pests and diseases down and share out the goodness in the soil.

Four beds make rotation simple: move each crop family along one bed every year. Pests and diseases lose their favourite food.

A simple four-year plan

Why this order? Peas and beans add nitrogen to the soil. The cabbage family follows because they’re hungry for it. Roots come next, as they prefer less rich soil. Potatoes help break up the soil ready for the next round.

With fewer than four beds, just do your best. Moving crops along one bed each year still helps. The main thing is not to grow the same family in the same soil two years running.

Watering and feeding

Watering

Raised beds drain faster than the ground. In warm weather, water every 2-3 days, and daily in a hot spell. Push a finger 5cm into the soil. If it’s dry, give it a good soak.

A soaker hose is a brilliant time-saver. Lay it along the bed, connect it to an outdoor tap with a timer, and it waters gently with no waste.

Mulching

Once plants are growing well (late May), spread a 5cm mulch of compost, straw or grass clippings. It cuts down on watering, keeps weeds down and feeds the soil as it breaks down.

Feeding

The compost in your mix feeds most crops through the first season. From midsummer, give hungry crops like tomatoes and courgettes a liquid tomato feed every two weeks.

The compost top-up each spring replaces what the crops used. Keep it up and your soil just keeps getting better.

A soaker hose under straw mulch. Together they save a lot of watering.

Raised bed jobs month by month

Common raised bed mistakes

Building too wide

A bed wider than 1.2m means stepping on the soil to reach the middle. That squashes it and spoils the drainage. Against a wall or fence, keep it to 60cm wide.

Making it too shallow

A 15cm bed is cheaper to fill but limits what you can grow. Roots, tomatoes and courgettes all want at least 30cm. Build to 30cm and fill it properly. You’ll get it back in better crops.

Forgetting the cardboard on grass

Grass and perennial weeds will push up through the soil within weeks. Lay thick cardboard on the bottom before you fill. It smothers what’s underneath and rots away. Don’t use plastic, which stops drainage.

Forgetting about slug protection

Slugs love raised beds as much as you do. The edges are easy to check, so go round on damp evenings and pick them off. Some gardeners also fit copper tape round the outside of the frame.

Growing too much in year one

It’s tempting to try everything at once. Start with four or five easy crops: lettuce, radishes, beans, tomatoes and strawberries. See what works for you before planning a full rotation. A bed filled with ericaceous compost is also perfect for growing blueberries, which need acid soil that’s hard to get in open ground.

Once your bed is built and planted, our seed sowing calendar will help you plan the year ahead.

Frequently asked questions

How deep should a raised bed be?

30cm suits most veg, including tomatoes, beans, lettuce and courgettes. Carrots and parsnips like 45cm so their roots can grow long. On concrete or paving, build at least 45cm deep to give roots enough room.

What is the best soil mix for raised beds?

Half topsoil and half garden compost. That gives you food for plants, good drainage and enough moisture. For Mediterranean herbs, mix in a little perlite for extra drainage. Top up with 5cm of fresh compost each spring.

What wood should I use for raised beds?

Larch, Douglas fir or pressure-treated softwood are all good choices. Larch and Douglas fir resist rot naturally. Modern pressure-treated timber is fine for growing veg and lasts for years. Avoid old railway sleepers, which may contain creosote, and pallet wood, which may have been treated with chemicals.

How much does it cost to build a raised bed?

A simple timber bed is cheap to build. The wood is usually the smaller cost, and a 1.2m x 2.4m x 30cm bed needs about 860 litres of soil mix to fill it. Larch, steel and brick cost more. Building several beds at once and buying soil in bulk brings the price down.

Do raised beds need drainage?

Yes, water must be able to drain away. Put beds straight onto soil so water soaks down naturally. On concrete or paving, add a 10cm layer of gravel at the bottom before filling. Beds that sit in water quickly cause roots to rot.

What grows best in raised beds?

Salads, herbs, root veg and climbing beans all do brilliantly. The warm, free-draining soil suits tomatoes, courgettes and peppers too. Quick crops like lettuce, radishes and spring onions make the most of the space.

How often should I water raised beds?

Every 2-3 days in warm weather, and daily in hot spells. Raised beds dry out faster than the ground. Push a finger 5cm into the soil, and if it’s dry, water well. A 5cm mulch of compost or straw means less watering.