Beginner's Guide to Growing Herbs in Pots

Why a pot makes the perfect herb patch

Most of the herbs we cook with come from thin, stony, free-draining ground in warm parts of the world. That is very good news for anyone with nothing more than a doorstep, a balcony or a small paved corner. A pot lets you build exactly the soil a rosemary or a thyme wants, and it lets you move the plant into shelter when the weather turns. You also get far fewer slugs, and no need to dig anything at all. Even a modest collection of six pots, arranged on a sunny patio, will keep a household in fresh herbs from late spring right through to the first hard frost.

The single most important rule is to match the plant to the conditions you actually have. Herbs grown in shade sulk, stretch and lose flavour, so watch your space for a day before you buy anything. Most culinary herbs want six hours of direct sun, though mint, parsley and chives will manage on four.

Six herbs that forgive beginner mistakes

Start with a short list rather than a whole herb collection. These are tough, useful and easy to find in garden centres or as seed.

• Basil — a tender annual, so treat it as a one-season crop and sow again in June. It loves warmth and rich compost, and hates cold water, so use water at room temperature.
• Mint — vigorous to the point of thuggish. Always give it its own pot, or it will swamp everything nearby. Partial shade suits it.
• Chives — a hardy perennial that comes back year after year in the same pot. Snip the leaves rather than pulling them, and remove the purple flowers if you want tender growth.
• Thyme — dry, gritty compost, full sun, and water only when the pot feels light. Common thyme and lemon thyme are both reliable.
• Rosemary — a woody shrub, not a soft herb. It needs a large pot, sharp drainage and very little feeding. It will survive a mild winter outdoors if kept out of standing water.
• Flat-leaf parsley — slow to germinate from seed, so buy a plant instead. It is a biennial, which means the second year it will bolt and go to seed; sow fresh each spring.

If you have room for two more, coriander (sow little and often, as it runs to seed fast in heat) and oregano are both worthwhile.

Pots, compost and drainage

Size matters more than style. A pot of 20–25cm across is the minimum for a single herb, and rosemary, sage or bay will want 30cm or more. Terracotta is excellent because it breathes and dries out quickly — ideal for Mediterranean herbs, though it means more watering for thirsty mint and parsley. Plastic holds moisture longer, which suits basil and chives.

Whatever you choose, drainage holes are non-negotiable. Cover them with a piece of broken pot or a few stones so compost does not wash through, then fill with a loam-based compost such as a John Innes No. 2, which holds its structure far better in a container than a light multipurpose mix. For thyme, rosemary, oregano and sage, mix in grit at roughly one part grit to three parts compost, and raise the pots onto feet or bricks so water never sits underneath.

Never use garden soil on its own. It sets like concrete in a pot and brings in weeds and pests.

Watering: the skill that decides everything

More container herbs are killed by kindness than by neglect. Overwatering drowns roots, turns leaves yellow and encourages fungus gnats. Underwatering is quicker to spot — leaves droop, then crisp at the edges — and quicker to fix.

Push a finger in up to the first knuckle. If it is damp, wait. If it is dry, water thoroughly until it runs out of the bottom, then empty the saucer after half an hour. In summer, a small terracotta pot in full sun may need water twice a day; a 30cm plastic pot of mint might need it every second day. Water in the early morning so the foliage dries before evening, which helps prevent mildew. On hot days, group pots together to shade one another, or stand them in a shallow tray of gravel that you keep damp.

Feeding, pinching and harvesting

Mediterranean herbs grown for flavour want a lean life; too much nitrogen produces lush, tasteless leaves. Give rosemary, thyme, sage and oregano a weak liquid seaweed feed once a month at most, and none at all in winter. Leafy herbs — basil, parsley, mint, chives — benefit from a fortnightly feed through the growing season.

Harvesting is what keeps plants bushy. Always pinch or snip the growing tips, cutting just above a pair of leaves, and take no more than a third of the plant at a time. Basil especially rewards this: pinching out the top set of leaves makes it branch, and removing flower buds as soon as they appear keeps the leaves sweet for weeks longer. Chives should be cut hard, about 3cm from the base, and they will regrow. For rosemary and thyme, snip small sprigs regularly rather than hacking off big branches, and never cut back into old, leafless wood, as it rarely reshoots.

Keeping pots going through winter

Hardy perennials — thyme, rosemary, sage, chives, oregano and mint — can stay outside, but their roots are far more exposed in a pot than in the ground. Move them against a sheltered wall, ideally on the sunny side of the house, and raise them off the ground. Water sparingly but do not let them dry out completely; a dry, cold wind is more damaging than frost. Tender basil will not survive, so either take cuttings in late summer to keep on a bright windowsill or simply start again from seed in spring. Come March, top-dress each pot with a couple of centimetres of fresh compost and the whole cycle begins again.