Why the kitchen windowsill is the perfect spot

A kitchen windowsill is one of the most underrated growing spaces in a British home. It is warm, it is light, and you will walk past it several times a day, which matters more than most gardeners admit. Herbs that sit in front of you get watered, pinched, chopped and noticed. Herbs at the end of a rainy garden path too often get forgotten.

The three easiest to start with are basil, mint and chives. All three cope with the fluctuating temperatures of a home, all three give you something to cut within a few weeks, and all three are far better fresh than anything you can buy in a plastic bag. With a little attention they will crop right through the year, though you should expect a slower, sparser harvest between November and February.

Getting the light right

Light is the single biggest factor in success, and it is where most windowsill herb gardens fail. Herbs want bright, direct light for at least six hours a day. A south-facing windowsill is ideal; east-facing is a good second. North-facing sills are too dim for basil and mint, and even chives will go pale and leggy.

If your only option faces north, or you are growing in deep winter when daylight is short and grey, a small LED grow light set on a timer for twelve to fourteen hours a day will transform results. It does not need to be expensive or complicated.

• Turn your pots a quarter turn every few days so plants grow straight rather than leaning hard towards the glass.
• Mind the glass in summer. A south-facing sill can reach 35°C or more behind closed glass, which will scorch leaves. Move pots back a little in July and August.
• Watch for draughts. A single-glazed sash window in an old house can chill roots overnight. A folded cloth behind the pots helps.

Choosing pots and compost

Use pots with drainage holes, always. A pretty pot without holes is a slow death sentence, because herb roots hate sitting in stagnant water. Set them on a saucer, but empty the saucer twenty minutes after watering rather than letting the pot stand in it.

Terracotta dries out faster, which suits rosemary and thyme. Plastic or glazed pots hold moisture longer, which suits mint and chives. Multi-purpose compost is fine, but a handful of grit or perlite mixed through improves drainage and reduces the chance of fungus gnats.

One important point: give mint its own pot. It spreads by underground runners and will smother anything sharing its compost within a couple of months. Basil, chives and parsley can be grown together in a wider trough if you keep them well spaced.

Watering without drowning them

Windowsill herbs are more often killed by kindness than neglect. The rule is simple: push a finger into the compost up to the first knuckle. If it feels dry at that depth, water. If it is damp, wait a day.

• Little and often beats a weekly flood. Small pots dry out quickly, especially near a radiator.
• Water in the morning where you can, so surplus moisture evaporates before the cooler evening air.
• Never let basil wilt completely. It rarely recovers well. Mint, by contrast, is surprisingly forgiving and will bounce back.
• Chives like consistent moisture but will rot if the compost stays sodden.

If your tap water is very hard, leave it in a jug overnight before using it. Basil in particular appreciates this.

Feeding, pinching and keeping the crop coming

From March to September, feed with a diluted liquid seaweed or general-purpose organic feed every fortnight. In winter, stop feeding altogether unless your plants are under a grow light and still putting on growth.

Harvesting is what keeps these plants productive, so be bold. Never strip a plant bare; take a few leaves from the top and sides and let the rest carry on.

• Basil: pinch out the growing tip above a pair of leaves to encourage bushy growth, and remove flower buds the moment you see them, as flowering signals the leaves to turn bitter. Take cuttings in late summer and root them in a glass of water on the sill to carry you through winter.
• Mint: cut whole stems down to about 3cm from the compost. It regrows fast and the trimmings make excellent tea.
• Chives: snip leaves to roughly 3cm above the base, never lower, and cut from the outside of the clump inwards. The pink flowers in late spring are edible and lovely scattered over salads.

Common problems and what to do

Small black flies hovering over the compost are fungus gnats, a sure sign of consistently wet soil. Let the surface dry out between waterings and cover the compost with a thin layer of grit.

Sticky residue and curling new growth usually means aphids or whitefly. Check the undersides of leaves and wipe them off with a damp cloth or a weak soapy spray. Pale, stretched, weak stems mean too little light, so move the pot closer to the glass or add a grow light.

Finally, think in successions. Sow a fresh pot of basil every six to eight weeks from spring onwards, and you will never face that sad moment when a tired old plant gives up in January and the shop-bought alternatives cost more than a decent bottle of wine. A windowsill of herbs is one of the cheapest, most rewarding pieces of gardening you can do, and it is only ever a step away from the chopping board.