Growing herbs on a kitchen windowsill

Why the kitchen windowsill is a growing space worth using

There is something satisfying about snipping basil straight into a pan of tomatoes, or tearing mint into a jug of water without a trip to the shop. A kitchen windowsill gives you that immediacy. It also gives you a front-row seat to watch plants grow, which makes it far easier to spot a thirsty parsley or a hungry basil before it sulks. In the UK, where outdoor herb growing can be a stop-start affair from April to September, a sunny indoor sill extends the season and keeps you in fresh leaves right through the darker months.

Pick the right herbs for your light

Not all windowsills are equal. A south-facing sill that gets six or more hours of direct sun will suit basil, rosemary and thyme. An east- or west-facing sill, with a few hours of gentle sun, is better for parsley, chives and mint. A north-facing sill is the trickiest; stick to mint and parsley, and accept slower growth. Basil is the classic windowsill herb, but it is also the fussiest. It hates cold draughts, resents soggy roots and will stretch towards the glass if you do not turn it. Parsley is more forgiving, though it is slow to germinate from seed — soaking the seeds overnight before sowing helps. Mint is the easiest of all, but it is a thug. Keep it in its own pot, because its roots will happily invade anything nearby.

Getting the setup right: pots, compost and drainage

Good drainage is non-negotiable. A pot without holes is a slow execution. Here is what you need:

• Containers at least 15cm across for basil and parsley, and 20cm for mint.
• Peat-free multi-purpose compost, mixed with a handful of perlite or horticultural grit.
• Drainage holes in every pot, plus a saucer underneath to catch drips.
• No garden soil straight from the border — it compacts in pots, drains poorly and may bring in weeds or pests.

Terracotta is breathable and looks lovely; plastic is lighter and holds moisture longer. Either works. If you are reusing old pots, scrub them with hot soapy water first. A small watering can with a fine rose is gentler on seedlings than a jug.

Planting and the first few weeks

You can sow seed or buy small plants. For speed, buy young plants from a garden centre or supermarket in spring and pot them on into slightly larger containers. If sowing, fill your pot to within 2cm of the rim, firm gently, water and then scatter seeds thinly. Cover with a fine layer of compost — just a dusting for basil, which needs light to germinate, and about 5mm for parsley. Keep the compost moist but not wet. A clear plastic bag over the pot helps hold humidity. Once seedlings have two sets of true leaves, thin them to the strongest few. Water from below by standing the pot in a saucer of water for ten minutes, then emptying the saucer. This encourages roots to grow down rather than linger on the surface.

Keeping herbs productive: turning, feeding and pinching

On a windowsill, light comes from one direction, so plants lean. Turn your pots a quarter turn every two or three days. This is the single easiest habit that keeps stems straight and growth even. Feed every fortnight from spring to early autumn with a liquid seaweed or balanced liquid fertiliser — basil and parsley are hungry, mint less so. Pinch out the growing tips of basil regularly; this stops it becoming a tall, leggy stalk and encourages side shoots. Remove any flower buds from basil and mint as soon as you see them, because flowering signals the leaves to turn bitter. Watch for pests: aphids cluster on soft new growth, whitefly flutter when you disturb the plant, and fungus gnats hover around wet compost. A diluted drop of washing-up liquid in water can deter aphids; sticky yellow traps catch whitefly. If a plant becomes badly infested, it is often kinder to bin it and start again than to wage a long war.

Harvesting and succession for a steady supply

Never strip a plant bare. Take no more than a third of the leaves at a time, and always cut above a leaf node so the plant can branch. For basil, snip whole stems just above a pair of leaves. For parsley, cut outer stems at the base. For mint, pinch the top few leaves. Regular harvesting keeps plants bushy and productive. To avoid a gap in supply, sow or pot up a new round every four to six weeks through spring and summer. In winter, growth slows, so reduce watering and stop feeding. If your kitchen is very warm and dry from central heating, group pots together on a tray of damp pebbles to raise humidity, and keep them away from radiators. With a little attention, a simple windowsill can give you fresh herbs for months — and a quiet daily pleasure every time you cook.