Start with the site, not the seed catalogue

Before you order a single packet of seed, spend a fortnight watching your plot. A kitchen garden lives or dies by three things: light, water and how easily you can get to it with a wheelbarrow.

Most vegetables want at least six hours of direct sun a day, and afternoon sun is more valuable than morning sun because it warms the soil and dries foliage, which helps against blight and mildew. Watch where the shadow of your hedge, shed or neighbour's conifer falls at midday in June — that is the shadow that matters. A patch that looks generous in February can be half shaded by midsummer.

Water access is the second test. Carrying cans from an outside tap 30 metres away gets old by the second week of July. A bed of vegetables will want roughly 10–20 litres per square metre per week in dry weather, which for a modest 30 square metre plot is a lot of trips. Site the garden within a hose run, or plan two or three water butts fed from shed and greenhouse roofs. Rainwater is also kinder to seedlings than hard tap water.

Finally, think about proximity. The best kitchen garden is the one you walk past on the way to the bins. If you can see it from the kitchen window, you will spot the pigeons, the aphids and the bolting lettuce before it is too late.

Lay out deep beds rather than long rows

Traditional allotment rows suit a rotorvator, not a household. For a cottage garden or smallholding, deep beds are far more productive per square metre and far easier to manage.

• Width: 1.2 metres is the practical maximum — you should be able to reach the middle from either side without stepping on the soil.
• Length: 3–6 metres. Long beds are efficient; enormous ones become a chore to weed in one sitting.
• Paths: 45–60 cm between beds, and at least 90 cm for the main route so a barrow passes comfortably. Bark chip or mown grass both work well.
• Orientation: Run beds north to south where you can. Tall crops then shade their neighbours for less of the day.

If your ground is heavy clay, sits wet in winter, or you garden on a slope, raised beds made from untreated timber are worth the outlay. Twenty to twenty-five centimetres of depth is ample for salads, roots, beans and most brassicas. On very thin or stony ground, go deeper.

Build the soil before you build the planting plan

Good soil is the whole game. Test the pH with a cheap kit: most vegetables are happiest between 6.0 and 7.0, and brassicas will sulk in acid ground. Lime in autumn if you need to lift it; add sulphur or plenty of compost if it is too alkaline.

Unless your plot is badly compacted, skip the double digging. Spread 5–8 cm of well-rotted manure or homemade compost over the surface each autumn or early spring and let the worms do the work. Stay off the beds when the soil is wet — compaction is the one mistake that takes years to undo. A permanent mulch of compost or straw suppresses weeds, conserves moisture and feeds the soil life that feeds your crops.

Set aside space for two compost bays and a leaf mould bin from day one. You will never have enough of either.

Grow what your household actually eats

This is where most new growers go wrong. It is easy to plant a whole packet of courgette seed and then drown in marrows by August. Sit down with the people you cook for and write a list of the vegetables you eat most weeks.

Then work backwards with rough numbers for a family of four:

• Courgettes: two or three plants, not ten.
• Runner beans: 20–30 plants will keep you picking from July to October, with plenty to freeze.
• Tomatoes: 12–20 plants outdoors under a south wall, more if you have a greenhouse.
• Salad leaves: sow a half-metre row every three weeks rather than a whole bed at once.
• Potatoes: 20–30 seed tubers in bags or a short bed gives a satisfying first earliness.

Give permanent space to crops that earn their keep year after year: rhubarb, asparagus, Jerusalem artichokes, and soft fruit such as blackcurrants, gooseberries and autumn raspberries. Put herbs near the kitchen door — rosemary, thyme, sage and bay are happier in pots or a gravel strip than in rich vegetable ground.

Plan succession, rotation and winter crops

A productive plot is never empty. Keep a simple four-group rotation — legumes, brassicas, roots, and potatoes with alliums — and move each group on by one bed every year. This disrupts pests and disease and balances what each crop takes from the soil.

Follow early potatoes or broad beans with leeks, kale or a late sowing of spinach. Sow salad, radish and turnips in small batches through the season. In autumn, plant garlic and overwintering broad beans, and keep a bed of winter greens under fleece or a cloche. A notebook, even a scrappy one, is the most useful tool you will own: record what you sowed, when it cropped, and what you would not grow again.

Tools, water and a realistic first year

You need less kit than the catalogues suggest. A spade, a digging fork, a draw hoe, a hand trowel, a rake, a watering can, a line and a few buckets will see you through. Add a wheelbarrow, a sharp knife for harvesting and a good pair of gloves.

Expect the first year to be rough around the edges. Weeds will win some weeks, slugs will take their share, and something you pinned your hopes on will fail entirely. Start with a manageable area — 30 to 50 square metres is plenty — get it working well, and expand next season. A small, well-tended kitchen garden will feed you far better than a large neglected one.