How to Grow Herbs on a Kitchen Windowsill

Why a Kitchen Windowsill Is Ideal for Herbs

Most of the herbs we cook with are tough, adaptable plants that evolved on rocky hillsides with poor soil and plenty of sun. They do not need a garden bed, a raised planter or a greenhouse. A windowsill with a few hours of daylight, a handful of small pots and a willingness to check on them every couple of days is genuinely enough to keep you in fresh basil, mint and chives for most of the year.

The other advantage is proximity. Herbs grown at the back of a garden get forgotten, then harvested in a panic when a recipe demands them. Herbs on the sill get pinched as you cook, which is exactly how they like to be treated. Regular, light picking keeps plants bushy rather than leggy, and the leaves you take are young, tender and full of oil.

Choose Herbs That Suit a Small Pot

Not every herb enjoys being confined, so start with the reliable ones and add others once you have a feel for the light in your kitchen.

• Basil — the classic windowsill herb. It loves warmth and bright light, hates cold draughts and sulks if its roots stay wet. Bushy varieties such as sweet Genovese work well in a 12–15cm pot.
• Mint — vigorous to the point of bossiness. Keep it in its own pot, because it spreads by runners and will smother anything sharing its compost. It tolerates shadier sills than basil.
• Chives — forgiving, hardy and productive. Snip the leaves rather than pulling them, and the clump will regrow again and again.
• Parsley and coriander — worth trying if you have a bright sill, though coriander bolts quickly in warm kitchens. Sow little and often rather than expecting one plant to last all year.
• Thyme, rosemary and sage — possible, but they prefer cooler, breezier conditions and leaner compost. They often do better in a porch or on an outdoor sill.

Pots, Compost and Drainage

Most windowsill herb failures come down to water sitting around the roots. Whatever pot you use, it must have drainage holes in the base, and it must sit on a saucer that you empty rather than leave full.

Use a peat-free multipurpose compost mixed with about a fifth horticultural grit or perlite. This keeps the compost open and reduces the risk of the soggy, compacted rootball that kills basil faster than anything else. A 10–13cm pot is plenty for a supermarket-bought herb you are repotting, and a 15cm pot suits a clump of chives or a well-grown mint.

If you buy a pot of herbs from the shop, split it. Those dense plugs of basil and parsley are several seedlings crammed together, and they will never thrive as they are. Ease the rootball apart gently and pot up two or three seedlings per pot, or plant them individually if you have the space.

Light, Warmth and the Turning Rule

Light comes from one direction on a windowsill, and plants will always lean towards it. Turn every pot a quarter turn every few days, or at least once a week, so stems stay upright and the plant grows evenly rather than stretching sideways into the glass.

A south- or west-facing sill is ideal for basil and coriander. East-facing sills are gentler and suit mint, chives and parsley well. North-facing sills are difficult in a British winter — growth will be slow and pale, so consider a small grow-light or move plants to a brighter room until spring.

Keep pots away from radiators, which dry the compost from below and scorch leaves, and away from single-glazed windows on frosty nights. Basil in particular will blacken and collapse after a night of cold draughts, so lift pots onto an inner sill or move them into the room after dark in winter.

Watering and Feeding Without Fuss

Check the compost with a finger rather than a timetable. If the top two centimetres feel dry, water until it runs through into the saucer, then tip the surplus away. Basil prefers to dry out slightly between waterings; mint and chives prefer to stay consistently moist.

Small pots dry quickly, so in summer you may need to water daily — sometimes twice on a hot day. In winter, cut right back and water only when the compost is genuinely dry, as soggy cold compost rots roots.

• Feed with a diluted liquid seaweed or general-purpose feed every two weeks from March to September.
• Stop feeding in winter, when growth slows and unused nutrients build up in the compost.
• Top-dress pots with a little fresh compost in spring if plants are staying put for another season.
• Watch for fungus gnats hovering over wet compost — let the surface dry out between waterings to break the cycle.

Harvest Little and Often

Frequent picking is what keeps windowsill herbs productive. Rather than stripping whole stems, take the tips: pinch or snip just above a pair of leaves, and the plant will branch from that point and produce two new shoots.

With basil, harvest from the top of the plant and remove any flower buds as soon as they appear — once basil flowers, leaf production slows and the flavour turns peppery. Never take more than a third of the plant at one time, and always leave the lower leaves to keep the plant feeding itself.

Mint responds well to being cut back hard; take the top two pairs of leaves regularly and pinch out the growing tips to encourage a fuller shape. Chives should be snipped about 2–3cm above the compost, using the outer leaves first and leaving the centre to regrow.

Picked this way, a modest sill of three or four pots will keep supplying you right through the growing season — and with a little care over winter, well into the following spring.