Sunlight Is Not Negotiable

Most vegetables are annual plants racing to produce fruit or storage roots in a single season, and they run that race on light. A bed in the wrong place cannot be rescued by better soil, better watering, or better plants.

The working figure is six to eight hours of direct sun a day for fruiting crops — tomatoes, peppers, courgettes, beans, cucumbers. Root crops manage on rather less. Leafy crops — lettuce, spinach, chard, most herbs — will produce usefully on four hours, and in hot climates actively prefer some afternoon shade.

Measure it before you build anything. Pick a clear day, look at the candidate spot every hour or two from morning until evening, and note when it is in full sun. Do this in the season you intend to grow in, because the sun sits far lower in winter and a fence or building that casts no shadow in June will cover the whole bed in March.

Two details people miss: deciduous trees are not a fixed quantity — a spot that is bright in early spring can be under full leaf canopy by June, which is exactly when the crop needs light — and tree roots extend roughly as far as the branches, competing for water and nutrients well beyond the shade line.

The Other Three Site Questions

Water. You will be carrying water in dry weather, and a bed at the far end of a large garden gets watered less than one by the tap. This sounds trivial and is one of the more reliable predictors of whether a first garden survives August. Site within reach of a hose if you possibly can.

Drainage. After heavy rain, look at where water sits. A patch that holds standing water for hours will rot roots. If the only available spot does this, a raised bed is the straightforward answer, since it lifts the root zone above the problem.

Shelter and access. Wind dries plants out, snaps tall crops, and knocks over supports; a fence, hedge, or wall on the windward side helps enormously. And make sure you can walk all the way around the bed, because a bed you can only reach from one side is a bed whose far half gets neglected.

A footpath’s worth of proximity to the house matters more than it should. Gardens that are visible from a window or passed on the way to the bins get noticed — you spot the wilting, the caterpillar, the ripe bean — while a plot behind the shed gets visited on Saturdays.

Start Much Smaller Than You Want To

The most common first-year mistake is scale. Enthusiasm in March produces a plot that becomes an unweedable obligation by July, and a garden that has visibly defeated you is a garden you stop visiting.

A bed of roughly 1.2m × 2.4m (about 3m²) is a realistic first year and produces a genuinely useful amount of food. Two of those is an ambitious first year. Containers on a balcony are a legitimate garden and a very sensible way to find out whether you enjoy this.

Width is a rule with a reason: no more than 1.2m across if you can reach from both sides, or 60–75cm if the bed is against a wall. The point is that you must be able to reach the middle without stepping on the soil. Walking on growing soil compacts it, destroys the air spaces roots need, and is remarkably hard to undo.

Leave paths of at least 45cm between beds — enough for your feet, a bucket, and a kneeling pad.

Raised Bed, Ground Bed, or Containers

A ground-level bed is free. You dig or mulch out what is there, improve the soil, and grow. It suits good existing soil and larger areas, and it dries out more slowly than a raised bed in hot weather.

A raised bed — timber, sleepers, stone, or metal, 20–40cm deep — is the usual recommendation for beginners, and for good reasons: you fill it with soil you choose rather than the soil you inherited, it drains well, it warms earlier in spring, it defines the space so nobody walks on it, and it is easier on your back. The costs are the materials, more frequent watering in summer, and the need to top it up as the contents settle each year.

Use untreated hardwood, naturally durable timber such as cedar or larch, or modern treated timber sold as safe for garden use. Avoid old railway sleepers and reclaimed timber treated with creosote, which is exactly what you do not want leaching into food crops.

Containers work better than people expect, on the condition that they are big enough. The universal container mistake is a pot too small: it dries out within hours in summer and roots have nowhere to go. As a rough guide, 20–30 litres for a single tomato plant, 10 litres minimum for most single crops, and wide shallow trays for salad leaves. Every container needs drainage holes, and containers use potting compost rather than garden soil, which compacts into a solid block in a pot.

Preparing the Ground

On grass or weeds, two approaches work.

The slow, easy one is sheet mulching: lay plain cardboard over the area with the tape removed, overlapping generously, wet it thoroughly, and pile 15–20cm of compost and organic matter on top. The grass dies in the dark, the worms pull the whole lot down, and you can plant into the compost layer almost immediately for larger plants. This is the least work by a wide margin.

The fast one is removing the turf with a spade in shallow slices and stacking it upside down somewhere to rot into loam.

Perennial weeds need dealing with properly, whichever route you take. Bindweed, couch grass, ground elder, and their equivalents regrow from any fragment of root left behind, and they will come up through cardboard and compost happily. Dig those out as completely as you can before you build a bed on top of them, and expect to keep pulling for a season.

Do not simply dig a bed and plant into it if the soil is heavy clay or thin sand — that is the next guide’s subject, and it is the difference between a bed that works and one that disappoints for three years in a row.