Growing Herbs in Pots on a Small Patio

Start with the sunniest corner you have

Herbs grown for flavour come from the Mediterranean hillsides, and they have long memories of that life. They want sun, they want air moving round their leaves, and they want soil that drains away quickly rather than sitting wet round their roots. A patio corner that catches the sun from mid-morning until early evening is ideal, especially if it sits against a wall or fence that holds a little warmth into the evening. A westerly or southerly wall is the best friend a pot of rosemary will ever have.

Before you buy a single plant, spend five minutes watching the light. Notice where the shadow of the house falls at ten in the morning and where it has moved to by four. Herbs will tolerate a bit of dappled shade, but a corner that never sees direct sun will give you pale, leggy plants with little scent and next to no flavour. If your only space is a shaded yard, it is still worth growing mint and chives, which are more forgiving, but keep your expectations modest.

Three herbs that earn their place

You can grow dozens of herbs in containers, but a small patio rewards restraint. Three plants done well will give you more than ten done badly, and these three cover most of what a kitchen actually needs.

• Rosemary is the backbone. A woody, evergreen shrub rather than a soft green herb, it will stand on a patio for years if it is not waterlogged. Look for a bushy young plant rather than a tall, single-stemmed one, and give it the largest pot you can reasonably manage — a 30cm to 40cm pot suits it well. It is superb with roast lamb, potatoes and anything off the barbecue.
• Mint is the thug of the herb world and must be treated accordingly. It spreads by underground runners and will happily colonise every pot on the patio if you let it share. Plant it in its own container, and do not be tempted to put it in with anything else. Spearmint is the best all-rounder for teas and salads; Moroccan mint makes a proper pot of tea.
• Thyme is small, tidy and quietly excellent. Common thyme and lemon thyme both thrive in shallow, gritty compost and prefer to be a little dry. A 20cm pot is plenty. It is the herb to reach for with chicken, mushrooms, tomatoes and roasted vegetables.

If you have room for a fourth, add flat-leaf parsley or chives. Both are useful, both are easy, and both cope with a touch more shade than rosemary or thyme.

Pots, compost and drainage

Terracotta is traditional for a reason: it breathes, it dries out faster and it looks right on a British patio. Glazed pots hold moisture longer, which suits mint but not rosemary. Whatever you choose, check that there is a decent hole in the base, and cover it with a broken piece of pot or a few stones so it does not silt up. Raising pots onto small feet or bricks helps water escape and stops the roots sitting in a puddle after a downpour.

Use a soil-based compost such as a John Innes number two, and mix in a good handful of horticultural grit per pot. Herbs that come from rocky hillsides hate rich, spongy, peat-heavy compost; it holds water, encourages soft floppy growth and dilutes the oils that give the leaves their scent. Lean and gritty is what you want. Do not add fertiliser at planting time, and go easy on it afterwards.

Watering: regular, but never soggy

Container herbs dry out far faster than plants in the ground, particularly in July, and a small patio can act as a heat trap. On a warm day a pot of mint may need watering twice. The reliable test is to push a finger into the compost up to the first knuckle: if it feels dry, water thoroughly until it runs out of the base, then stop. Little daily splashes only wet the surface and encourage shallow roots.

Rosemary and thyme would rather be a touch dry than wet, so if in doubt, wait a day. Mint is the opposite and will wilt dramatically to tell you it is thirsty — a useful alarm bell, and it usually recovers within an hour of a good drink. A saucer under mint is fine; under rosemary it is a shortcut to root rot. Feed rosemary and thyme once in late spring with a weak liquid feed, and give mint a little more regularly through the growing season.

Harvest often to keep plants bushy

The single most common mistake with potted herbs is being too polite with them. Regular picking is what makes a plant branch, thicken up and produce more leaf. Left unpruned, rosemary goes woody and leggy, mint runs to flower and thyme flops open in the middle.

Snip the tips of rosemary stems regularly, taking no more than a third of the growth at a time and always cutting just above a pair of leaves. Pinch out the top of mint shoots to encourage side growth, and strip leaves from the top down. With thyme, trim the whole plant lightly after flowering and use the cuttings. Never cut back into old, leafless wood on rosemary or thyme; it rarely regrows.

Pick in the morning, after the dew has dried but before the sun gets fierce, when the oils are at their strongest. Use what you cut, or freeze it in ice cubes with a little water. Come autumn, move the pots closer to the house for shelter and cut back on watering, and you will carry the same plants through to next spring.