Growing Herbs in Pots on a Kitchen Windowsill

Why the Kitchen Windowsill Beats the Greenhouse

Most smallholders have a greenhouse, a cold frame and a couple of raised beds, yet the herbs we actually use day to day are the ones within arm's reach of the kettle. A south- or south-west-facing windowsill gives six to eight hours of decent light through spring and summer — the equivalent of a very good herb bed, minus the slugs. A west-facing sill will do for parsley and chives. A north-facing one will grow you a leggy, sulking basil and very little else, so be honest about which side of the house you are working with.

Potted herbs are also out of reach of slugs and vine weevil, and you can check them in seconds each morning. Keep them a few centimetres back from the glass in summer, though: a south-facing window can act like a magnifying glass and scorch the leaves on a hot afternoon.

Picking Herbs That Earn Their Space

Not everything suits a pot. Rosemary, thyme and sage want gritty, dry conditions and plenty of root room; they sulk in a small sill pot and resent the humidity of a working kitchen. The three that genuinely thrive indoors are:

• Basil. Wants warmth, sun and a light, free-draining compost. A supermarket pot will be crammed with dozens of seedlings — split it into three or four smaller pots and you will get far more leaf.
• Parsley. Flat-leaved or curly, it is a biennial, so it runs to seed in its second year and needs replacing. More tolerant of shade than basil, and happier in slightly damper compost.
• Chives. Practically indestructible. They die back in winter and return in spring, and you can cut them hard again and again.

Add mint if you have the room, but always in its own pot — the roots run, and it will swamp anything sharing its compost.

Pots, Compost and Getting the Drainage Right

Use pots at least 15cm across for parsley and chives, and 12–15cm for basil, with a proper drainage hole in the base. Terracotta dries out faster and looks better; plastic holds moisture longer and sits more securely on a narrow sill. Whichever you choose, stand it on a saucer with a few pebbles or a folded piece of kitchen roll so the roots are never sitting in a puddle.

Fill with a peat-free multipurpose compost mixed with roughly a quarter by volume of horticultural grit or perlite. Compost straight from the bag compacts in small pots and stays wet at the bottom while drying at the top, which is the single most common reason windowsill herbs fail. If you are reusing pots, scrub them first — damping-off and root rot both lurk in old compost.

Watering Sparingly, Feeding Monthly

Overwatering kills more windowsill herbs than drought ever does, and basil in particular detests wet feet. The reliable test is weight: lift the pot. A dry pot is startlingly light. Push a finger 2cm into the compost — if it feels damp, walk away and come back tomorrow.

In summer, expect to water every two or three days; in winter, once a week or less. Water slowly from the top until a little runs into the saucer, then empty the saucer after twenty minutes. Never leave them standing in water, and never water to a schedule — the plant and the weather set the rhythm, not the calendar.

Feed once a month from March to September with a weak liquid feed. A seaweed or general-purpose tomato feed diluted to half the recommended strength is ample. More than that gives you soft, floppy growth and, in basil, a marked loss of flavour. Stop feeding altogether over winter, when growth slows to almost nothing.

Harvest Often to Keep Them Bushy

Herbs are cut-and-come-again crops: the more you take, the more you get. Where you cut matters, though.

• Basil: pinch out the growing tip just above a pair of leaves, and two shoots will break from that point. Never take more than a third of the plant at once, and pinch out flower buds the moment you spot them.
• Parsley: cut outer stems at the base, about 2cm above the compost, working from the outside in. The centre keeps producing. Remove flowering stems as soon as they appear.
• Chives: snip leaves 2–3cm above the base with scissors rather than yanking, and take the clump down evenly. In summer they will be back within a fortnight.

Little and often beats one big harvest. Ten stems snipped every few days keeps plants productive for months, whereas stripping a plant bare sets it back by weeks.

Keeping the Windowsill Productive Through the Year

In autumn, bring tender herbs indoors before the first frosts and check the undersides of leaves for aphids and whitefly. Chives will die back naturally — that is normal, and they return from the roots in spring. Keep basil above roughly 20°C, away from cold glass and draughts, and accept that it will struggle in a chilly kitchen.

Sow a fresh batch of parsley and basil indoors in February or March on a warm sill to replace tired plants, and start chives in small pots at the same time. A succession of three or four pots per herb means there is always something to cut. There is nothing quite like stepping two feet from the chopping board to a fistful of chives for an omelette — and that, really, is the whole point of growing them there.