How to Start a Raised Bed Vegetable Garden

Why raised beds are a smallholder's friend

If you have heavy clay, thin chalk or a garden that floods every winter, a raised bed is the kindest thing you can do for your vegetables. The soil in a raised bed warms up two or three weeks earlier in spring than the ground around it, which means you can sow radishes, lettuce and early carrots while your neighbours are still waiting for the frost to leave. Drainage is better too, so winter waterlogging is far less of a problem. And because you never walk on the growing area, the soil stays loose and crumbly, letting roots push down freely. For anyone with a small plot, a bad back or a determination to grow more of their own food, raised beds are a practical, rewarding place to start.

Pick the sunniest spot you can find

Vegetables are sun worshippers. Most of the crops you will want to grow need at least six hours of direct light a day, so watch your garden carefully before you commit to a position. A south-facing wall or fence is ideal, but east or west will do at a push. Avoid the shadow of sheds, hedges and mature trees — not just for the shade they cast, but for the roots and rain they steal. You also want a spot that is easy to reach with a wheelbarrow, a hose and a basket of tools. If the only level patch is at the bottom of the garden, that is fine, but think about how you will get compost there. Shelter from strong winds helps too, especially if you plan to grow tall crops like runner beans or sweetcorn.

Size, shape and layout

A good working width for a raised bed is 1.2 metres. That lets you reach the middle from either side without stepping on the soil. Length is up to you — 2.4 metres is a useful size, but even a 1 metre square will grow a surprising amount. If you are building more than one bed, leave a path of at least 60 centimetres between them so you can kneel, wheel a barrow and move a hose without a struggle. Timber is the traditional choice; untreated boards will rot in time, so many growers use pressure-treated wood or oak. Avoid old railway sleepers unless you know their history, as some contain tar-based preservatives. Bricks, stone or woven willow panels also work well. Whatever you choose, make sure the sides are sturdy enough to hold wet compost — it is heavier than you think.

Filling your beds without breaking the bank

You do not need to fill the whole depth with shop-bought compost. A layer of rotten logs, prunings and cardboard at the bottom will rot down over time and save a fortune. On top of that, use a mixture of well-rotted manure, garden compost and a good peat-free multipurpose compost. Aim for a blend that holds moisture but drains freely. If you are filling a bed that sits on soil, you can simply loosen the ground beneath and top it up with 20–30 centimetres of compost — worms and roots will find their way down. For beds on concrete or paving, you will need a deeper fill, around 30–40 centimetres. Then let the bed settle for a week or two before planting. A final sprinkle of blood, fish and bone or a handful of chicken manure pellets will give your crops a gentle start.

Start with easy, rewarding crops

Your first season should be about building confidence, not chasing prize-winning parsnips. Choose crops that germinate reliably, grow quickly and do not sulk. Salad leaves, radishes, spring onions and beetroot are all excellent. Courgettes and runner beans are generous once they get going, though they need space and plenty of water. Garlic and shallots can go in during autumn or early spring. Herbs such as parsley, chives and mint (keep mint in a pot, or it will take over) are happy in a raised bed too. Here is a simple starter plan:

• Early spring: sow radishes, lettuce, spinach and broad beans.
• Late spring: plant out courgettes, runner beans and sweetcorn.
• Summer: keep sowing salad leaves every few weeks for a continuous crop.
• Autumn: plant garlic, winter lettuce and overwintering onions.

Do not overcrowd. A raised bed may look empty at first, but plants need air and light. Follow the spacing on the seed packet, even if it feels generous.

Looking after your raised bed through the year

Raised beds dry out faster than open ground, especially in a hot spell, so water deeply once or twice a week rather than little and often. A layer of garden compost or straw mulch on top will lock in moisture and keep weeds down. Slugs are the main enemy in most British gardens — go out with a torch after rain and pick them off, or set a beer trap. Netting protects brassicas from pigeons and cabbage white butterflies. At the end of the season, pull out spent plants, add a layer of compost and let the worms do their work. If you can, sow a green manure such as field beans or grazing rye over winter; it will smother weeds and return goodness to the soil in spring. With a little care, a raised bed will reward you for years, and each season will teach you something new about your own patch of land.