A north-facing windowsill has a reputation problem. It never gets direct sun, it feels cold in January, and most of the herb pots sold in garden centres were raised somewhere much brighter. Yet it is also the only bit of growing space many of us have indoors — and with the right plants and a little discipline, it will keep you in parsley, mint and chives right through to spring.

What a north-facing windowsill actually offers

Light on a north-facing sill is diffuse, never direct. That suits leafy herbs that evolved on woodland floors or beside streams, and it rules out the sun-lovers most of us try first.

Before you plant anything, watch your sill over a full day. North-facing is rarely exact: you may catch a stripe of early sun in midsummer and none at all in December. The corners of a window are darker than the centre, and a sill shaded by a hedge or a wall is darker still. Clean the glass, too. A winter's grime and condensation can cost you a surprising amount of the light you do have.

Temperature matters as much as light. A sill above a radiator is warm and dry; one beside single-glazed glass is cold and draughty. Most herbs tolerate cool. Very few cope with hot, dry air and low light at once, which is why basil sulks in a heated kitchen in January and picks up again in March.

The herbs that will cope

Stick to soft-leaved, shade-tolerant culinary herbs. These are the ones that earn their windowsill space:

• Mint — the standout performer. Spearmint and Moroccan mint grow happily in shade and will keep producing small leaves all winter. Keep it in its own pot; it spreads.
• Parsley — flat-leaved or curly both work. Slow to start, steady once going, and generous with cut-and-come-again picking.
• Chives — fine on a north sill, though they crop best after a cold spell, so a chilly window is an advantage.
• Chervil — gentle aniseed flavour, genuinely shade-tolerant, and one of the few herbs worth sowing in late summer for winter cutting.
• Coriander — grows, but grows soft and leggy, and bolts quickly in warmth. Sow little and often rather than trying to keep one plant going.
• Lemon balm — tough, fragrant, happy in low light. Confine it to a pot.
• Sorrel — broad leaves with a sharp, lemon edge; one of the better shade plants for a big pot.
• Wild rocket and watercress — both enjoy damp shade and will give you peppery leaves for salads.
• Basil — borderline. It will survive, but expect smaller leaves and long gaps between them. Pinch it often and keep it as close to the glass as you can.

Which herbs to leave for a sunny sill

Rosemary, thyme, sage, oregano, lavender and French tarragon all come from hot, bright, dry places. On a north-facing windowsill they stretch towards the glass, pale and thin-stemmed, and they rot easily in compost that stays damp for weeks. If you have a south-facing kitchen window, give them that instead. Otherwise grow them outdoors in a well-drained pot and keep the north sill for the leafy herbs above.

The stretching has a name — etiolation — and it is the clearest sign a plant is not getting enough light. Long gaps between leaves, weak stems, a plant that leans hard to one side: all of it means move it closer to the glass or accept that it belongs elsewhere.

Watering: where most pots are lost

In low light, plants use far less water. Compost that would dry out in three days on a sunny sill can stay wet for a fortnight, and that is how roots drown.

1. Check before you water, every time. Push a finger two centimetres into the compost, or lift the pot and feel the weight.
2. Water thoroughly when the top of the compost is dry, then let it drain. Little sips every day are worse than a proper soak once a week.
3. Never leave pots standing in a saucer of water. Empty it twenty minutes after watering.
4. Use room-temperature water. Cold tap water on a cold windowsill is a shock.
5. Water in the morning so surplus moisture has the day to evaporate.
6. Cut back hard in December and January — you may water once a week or less.

Terracotta pots and a handful of grit mixed through the compost help anything woody or drought-tolerant. Mint, parsley and chervil prefer to stay a little damper, so plastic pots suit them fine.

Feeding, potting on and pinching

Feed only when plants are actively growing. From March to September, a balanced liquid feed at half the strength on the bottle, every two to three weeks, is plenty. Stop completely in midwinter; feeding a plant in low light produces weak, sappy growth that attracts pests.

Pot on when roots appear at the drainage holes, going up just one size — about two centimetres wider. A huge pot of wet compost around a small rootball is a recipe for rot.

Pinch out the growing tips regularly, taking the top pair of leaves just above a leaf joint. This is the single most useful thing you can do on a north sill: it turns one thin stem into a bushy plant, and it gives you something to cook with. Snip off coriander flower buds as soon as they appear to keep the leaves coming.

Rotating pots, and why it matters

Light arrives from one direction only on a windowsill. Leave a pot alone and it will lean, the far side will yellow, and you will end up with a lopsided plant on a bare stem. Turn every pot a quarter turn every couple of days, and shuffle the pots along the sill so each one spends time near the glass. Short pots go at the front; anything tall is a shade-thrower for whatever sits behind it.

Getting a crop through winter

Lower your expectations and you will not be disappointed. From November to February, growth slows to almost nothing, and a few sprigs at a time is a realistic harvest.

• Pick leaves from the outside of the plant and leave the growing centre alone.
• If chives look tatty, cut them back to a few centimetres and they will usually reshoot.
• Mint can be cut back hard; on a windowsill it often stays nearly evergreen.
• Split a supermarket pot of parsley or coriander into three or four smaller pots, teasing the roots apart, and you will have plants that last far longer than the original.
• Sow small pinches of chervil and coriander every three weeks for a steady supply of tender leaves.
• Move pots off the glass on frosty nights, and keep them away from radiators.
• Watch for fungus gnats rising from wet compost, and for aphids on soft new growth. Rinse leaves under a lukewarm tap and let the compost dry a little more between waterings.

A small LED grow light will help basil and other hungry plants in December, but it is optional. The herbs listed above will manage without one.

Start with three pots

Mint, parsley and chives. Buy them as small plants rather than seed for your first winter, pot them into a decent peat-free compost, stand them on the brightest part of the sill, and check them with your finger before you reach for the watering can. Turn them every other day, pinch the tips, and feed nothing until spring. That is enough for a handful of herbs on a gloomy January evening — and next year you will know exactly which spot on that sill works best.

Photo: Julia Sakelli / Pexels