Why Put Herbs by the Kitchen Door

There is a particular pleasure in cooking with herbs you have just cut, still warm from the sun and smelling of the plant they came from. The trick is to make that harvest effortless. A collection of generous pots set within a few paces of the back door does exactly that. You step out with a pair of scissors, snip what you need, and you are back at the hob before the pan has heated through.

Rosemary, mint and thyme are the ideal trio for this. They are forgiving, they crop over a long season, and each one brings a different scent to the doorstep — resinous, cool and peppery in turn. Brushing past them on the way to the bins or the washing line releases oils into the air, and that small daily fragrance is worth as much as the cooking. Growing them in containers also solves the problem of awkward soil: whether you have heavy clay, shallow chalk or nothing but paving, a pot gives you control.

Choosing Pots With Room to Grow

Most disappointing herb pots fail for one reason: the container is too small. A cramped root run dries out in an afternoon, heats up dangerously in July and leaves the plant stunted and woody. Be generous. Nothing smaller than 30cm across and 30cm deep will do, and 35–40cm is better still for rosemary.

• Rosemary grows into a small shrub with a woody frame, so give it the largest pot you can lift — 35–40cm wide, holding 25 litres of compost or more.
• Thyme is lower and spreads sideways rather than down. A 25–30cm pot, at least 20cm deep, suits it well.
• Mint is a traveller and will fill whatever it is given, sending runners in every direction. Give it its own pot, or sink a smaller pot inside a larger one so the roots stay contained and the mint cannot smother its neighbours.

Terracotta looks handsome and its weight keeps tall rosemary upright in a breeze, but it dries out faster than glazed stoneware. Whatever you choose, check for a drainage hole, add a layer of broken crocks at the base, and stand the pots on feet so water never sits beneath them.

The Right Compost for Each Herb

Rosemary and thyme come from Mediterranean hillsides and hate sitting wet. Use a loam-based compost such as John Innes no. 2, mixed with about a quarter horticultural grit by volume. The grit does two jobs: it opens up the texture so surplus water drains freely, and it adds weight so a top-heavy rosemary does not topple.

Mint wants the opposite. It enjoys rich, moisture-retentive ground, so use a peat-free multipurpose compost bulked out with a little garden compost or well-rotted manure and a handful of John Innes no. 3. Top-dress all three pots with a thin layer of grit or gravel. It suppresses weeds, keeps the collar of the plant dry and looks tidy.

Planting Up and Finding the Spot

Fill each pot to about a third with compost, firm it gently, then set the plant in so the top of its rootball sits roughly 2cm below the rim — that leaves room for watering. Fill around the roots, firm again with your fingers, and water well until it runs from the base. Leave a gap between pots so air can move around the foliage; good airflow is the best defence against mildew.

Position them in full sun, against a warm wall if you can manage it. Rosemary and thyme want at least six hours of direct light a day, and both are happiest in the shelter of a south- or west-facing wall. Mint is more tolerant of light shade, though it will be leafier and more fragrant in sun.

Watering, Feeding and Everyday Care

In summer, check pots daily. Push a finger in to the second knuckle: if it is dry, water until it runs through. Rosemary and thyme prefer to dry out slightly between waterings, while mint should never be allowed to wilt. In very hot spells, mint may need water twice a day.

Feeding should be light. Too much nitrogen gives you lush, flavourless leaves. A weak liquid seaweed feed once a month from May to August is plenty for rosemary and thyme; mint enjoys a fortnightly dose. Trim thyme after flowering to keep it bushy and stop it going leggy, and pinch out the growing tips of rosemary regularly. Watch for rosemary beetle, whose metallic green and purple stripes are unmistakable, and pick them off by hand.

Harvesting Well and Keeping the Supply Going

Never take more than a third of a plant at once. Snip stems just above a pair of leaves, which encourages branching, and always cut from the top rather than stripping the woody base. Regular picking keeps all three productive; an untouched mint quickly turns tough and tired.

Surplus freezes beautifully — chop the leaves into ice cube trays, cover with water and use the cubes straight in stews. Thyme and rosemary also dry well in small bunches hung somewhere airy and dark. As autumn closes in, raise the pots onto feet, cut watering right back and move them against the wall for shelter. Mint will die back completely; cut the stems to the ground and it will return, vigorous as ever, in spring.