Why herbs work harder than almost anything else in the garden

If you have room for only a few plants, herbs are the ones to choose. They give you something for the kitchen, nectar and pollen for insects right through the summer, and — if you resist the urge to tidy them away — seed heads that feed birds well into winter. Three herbs in particular do all of this beautifully in a British garden: chives, fennel and thyme. None needs much space, and all are happy in pots if your garden is a balcony or a small courtyard.

The single most useful thing you can do is simple: let some of your herbs flower completely before you cut them for the kitchen. A herb that is constantly trimmed never feeds anything. Set aside part of each clump for wildlife and harvest from the rest.

Chives: an early wake-up call for pollinators

Chives are usually the first of the three to flower, opening their tight mauve pom-poms from late spring into early summer. Those round heads are easy landing pads, and bumblebees, solitary bees and hoverflies make straight for them. Because they bloom when relatively little else is open, they are worth their weight in gold.

• Grow them in full sun or light shade, in ordinary soil or a pot. They are unfussy.
• Cut a clump back hard — to about 5cm — straight after flowering and you will often get a second flush of leaves and, in a good year, a few more flowers.
• Leave at least one clump to flower fully and set seed rather than cutting it. The dried heads stand well into autumn and give small birds somewhere to perch and forage.
• Divide congested clumps every three or four years in spring; the offsets establish quickly.

Fennel: the best herb in the garden for birds

If you grow only one herb for wildlife, make it fennel. It is a tall, feathery umbellifer that reaches 1.5–2m in a good year, and from midsummer carries flat, saucer-shaped heads of tiny yellow flowers. Those open heads are a landing strip for hoverflies, lacewings, parasitic wasps, honeybees and solitary bees — an entire aerial clean-up crew for your garden.

Then comes the second act. The flowers turn into ribbed green seeds that ripen to brown through early autumn, and goldfinches, greenfinches and house sparrows will strip them. Leave the stems standing and the birds will keep coming back through the winter.

Fennel needs sun and soil that drains. It self-seeds readily, sometimes enthusiastically; pull seedlings where you don't want them while they are small, or leave a couple to replace the parent. Bronze fennel is just as valuable and looks superb against a dark hedge. If you like to save seed for the kitchen, keep fennel away from dill so the two don't cross.

Thyme: small, tough and beloved by bees

Thyme is the herb for a hot, dry, sunny spot. Given sharp drainage it will flower for weeks in early and midsummer, and its tiny blooms are worked constantly by honeybees and small solitary bees. Creeping thymes are excellent between paving stones or spilling over a wall, where the scent of the leaves is released as you brush past.

• Plant in gritty, free-draining soil or a gravel garden. Thyme sulks and rots in heavy, wet ground.
• Do not feed it and do not enrich the soil — lean conditions keep both the flavour and the flowers coming.
• In containers, use a loam-based compost with plenty of horticultural grit mixed through.
• Trim lightly after flowering to keep plants bushy, but leave a good proportion of the flower stems to stand.

Thyme is also thoroughly drought-tolerant, which matters more with every dry summer.

Getting the harvest balance right

The trick is not to choose between the kitchen and wildlife, but to divide your plants. A workable approach:

• Grow at least two or three plants of each herb, or one decent-sized clump.
• Harvest leaves from one plant, or one side of a clump; let the other flower and set seed.
• Pick leaves in the morning when the oils are strongest, and never take more than a third of a plant at once.
• Stagger plantings by a few weeks so flowering is spread across the season rather than happening all at once.
• Once flowers fade, resist deadheading everything. Seed heads feed birds and hold their shape through frost.

Winter, soil and a few final touches

In autumn, cut only some of your herbs back. Leave stems standing to around 15–20cm through the winter: hollow stems and seed heads shelter overwintering insects and give birds somewhere to feed and perch. Tidy the rest in early spring, just as new growth starts.

Keep the garden free of pesticides — even a small spray on a flowering herb can undo weeks of good work. Provide a shallow dish of water with a few stones in it for drinking. Plant in groups rather than singly, as insects find patches of flowers far more easily than isolated ones.

Then sit back with a cup of tea and watch. Within a season, a modest patch of chives, fennel and thyme will be busier than anything else in the garden.