How Much to Grow to Feed a Family

The single most common mistake new growers make isn't killing their plants — it's the maths. They sow a whole packet of courgette seed, plant out a dozen seedlings, and spend August leaving carrier bags of marrows on the neighbours' doorsteps. Meanwhile they've sown one short row of carrots that's gone in a single Sunday lunch.

Getting the numbers roughly right from the start saves space, seed, effort and a lot of guilt. This guide gives you realistic plant numbers for a family of four, the crops genuinely worth growing in bulk versus a token few, and how to scale it all to your own household.

Why "how much" matters

Grow too little and the garden feels pointless — a handful of beans isn't a meal. Grow too much and you hit a glut: more of one crop than anyone can eat, freeze or give away before it spoils. Both outcomes quietly put beginners off.

The classic offender is the courgette. A single healthy plant can produce 20 or more fruits over a summer, and they come thick and fast in July and August. Two plants is plenty for a family of four; three is generous; anything more and you're running a courgette charity. It's the perfect example of how a "more is better" instinct backfires.

The honest aim isn't self-sufficiency on day one — it's a steady supply of the things you actually like eating, spread across the season rather than arriving all at once. That last part matters as much as the totals, which is why successional sowing sits alongside plant numbers as the other half of the puzzle. A short row of lettuce every fortnight beats a giant bed that all hearts up in the same week and then bolts.

A crop-by-crop guide to plant numbers for a family of four

These figures assume a family of four with average appetites, growing for fresh eating plus a little to store or freeze. They're a sensible starting point, not gospel — adjust up or down once you've seen a season for yourself. UK timings throughout; check sowing dates against the planting calendar and your local last frost date.

Tomatoes — 4 to 6 plants. This keeps a family in fresh tomatoes through summer and into autumn. Cordon (indeterminate) types crop over a long season — a single plant can give 3–4 kg in a good year. Want enough for sauces and passata to freeze? Push to 8–10 plants and grow a reliable cooking variety like 'Roma' alongside your salad types.

Courgettes — 2 plants. As above: two is the magic number. Pick them small and often at around 10–15 cm and they keep coming.

Runner and French beans — 8 to 12 plants. Beans are excellent value for space because they climb. A double row up a wigwam of canes keeps a family in fresh beans through August and September, with a surplus to freeze. Pick every few days so the plants keep flowering.

Broad beans — a 3 m double row. Broad beans are one of the first proper harvests of the year. A 3 m double row (roughly 30–40 plants) gives several good pickings; autumn-sown rows crop earlier in June.

Peas — a 3 m row, sown twice. Peas lose sweetness within hours of picking, so home-grown are a treat. The yield per plant is modest, though, so sow generously — a 3 m row in spring and another in early summer keeps them coming.

Potatoes — depends on type. Potatoes take a lot of room for the return, so most beginners grow earlies for the joy of new potatoes rather than a year's supply. A 3 m row of first earlies (around 10 seed potatoes) gives several meals of new spuds. For maincrop storage potatoes you'd need a far bigger area — be realistic about whether it's worth the ground.

Salad leaves — sow little and often. Don't think in plants, think in pinches of seed. A short row or a single seed tray of cut-and-come-again lettuce and mixed leaves, resown every 2–3 weeks from March to September, keeps a salad bowl going all season. This is the crop successional sowing was made for.

Onions — 40 to 80 sets. A family gets through a lot of onions. Planted from sets in spring, 40–80 bulbs will see you well into winter once cured and stored. They store for months, so they're worth growing in quantity.

Garlic — 1 to 2 bulbs' worth of cloves. Split into individual cloves, one or two bulbs of seed garlic planted in autumn gives 15–25 bulbs the following summer — a useful chunk of the year's cooking.

Carrots and beetroot — sow in succession. A 3 m row of carrots every month, and a couple of short rows of beetroot, keeps roots on the table without a glut. Both store well, so any surplus isn't wasted.

Kale, cabbage and other brassicas — 6 to 10 plants each. Hardy kale and cabbage earn their space by feeding you through the lean winter months when little else is growing. Six to ten well-spaced plants of each gives steady pickings; kale in particular keeps cropping for months from a single planting.

The crops worth growing a lot of vs a little

Not all crops deserve equal ground. A few principles help you weight your space sensibly.

Grow a lot of: crops that store or freeze well, that you eat constantly, and that give a strong return for the space. Onions, garlic, maincrop beans, kale and winter brassicas all fit — they either keep for months or crop over a long stretch, so a glut never goes to waste. These are also the crops that make the biggest dent in the shopping bill, which the cluster's guide to growing to save money digs into.

Grow a little of: crops that come all at once, don't store, or are cheap to buy anyway. Courgettes, lettuce and salad leaves should be sown in small, frequent batches rather than big single sowings. Maincrop potatoes are cheap in the shops and greedy for space, so many growers skip them and grow earlies for flavour instead.

Grow because they're better home-grown: some crops are worth a slot purely because the shop versions are a pale imitation. Peas eaten minutes from the pod, tomatoes ripened on the vine, new potatoes dug the same morning, and fresh-cut salad all fall here. The quantities can be modest — it's the quality that justifies them.

A quick way to decide: for each crop ask "does this store, and do we eat it often?" Two yeses means grow plenty. Two nos means grow a token amount, or buy it.

Using the yield calculator

Plant numbers are a guide, but kitchen-garden maths gets fiddly once you're juggling several crops, a particular plot size and a household that isn't exactly four people. That's where the yield calculator earns its keep.

Tell it which crops you want and how many people you're feeding, and it works back from realistic UK per-plant yields to suggest how many plants and how much row length to sow. It's far quicker than scaling these figures by hand, and it stops the two failure modes — a glut and a gap — before you've sown a single seed.

Pair it with the raised bed planner if you're working out whether your beds can actually fit what you've planned. Often the calculator reveals you've planned for more than your space holds, which is a far better thing to discover in February than in June.

Scaling to your household

The family-of-four figures above are easy to flex.

Smaller households can simply roughly halve the quantities — but keep at least two courgette plants and don't drop salad sowings below a steady trickle, or you'll find yourself buying the very things you set out to grow. One or two people often do best concentrating on a few high-value, long-cropping plants rather than a long thin row of everything.

Larger families scale up the bulk and storage crops most — more onions, more beans to freeze, more winter brassicas — while the fresh-eating crops like tomatoes and salad rise more gently. Storage capacity becomes the limit as much as ground does, so it's worth reading up on storing your harvest before you commit a big bed to maincrop onions or squash.

Whatever your size, start smaller than feels exciting in spring. It's far easier to expand a bed next year than to keep on top of a plot that's outgrown you by July. A well-tended small garden feeds a family better than a weedy big one.

Once you've settled on your numbers, slot them into the season properly: the cornerstone grow-your-own year plan shows when each of these crops goes in and comes out across a UK year, so your quantities arrive spread through the season rather than all in one overwhelming fortnight. Get the how-much and the when working together, and the garden stops being a chore and starts being a larder.