Attracting beneficial insects to your garden

Pest control and pollination are two of the most important services a garden needs — and insects provide both for free, without chemicals, without plastic bottles, and without side effects, if you give them what they need to thrive.

Why beneficial insects matter

Most insects that visit a garden are either neutral or actively helpful. The ones most gardeners fixate on — aphids, vine weevils, cabbage white caterpillars — represent a small fraction of the insect life that passes through or lives in a typical garden. Treating a garden as something to be defended against insects, with pesticides and barriers, removes the good alongside the bad and often makes the underlying problem worse.

Natural pest control works on the same ecological principles as everything else in a functioning ecosystem: predators follow prey. Where aphids are present, ladybirds, lacewings and hoverfly larvae will follow if there is habitat for them. Where slug populations are high, ground beetles, slow worms and hedgehogs will find good feeding if not disturbed. The challenge for gardeners is not how to fight these dynamics but how to work with them — and that starts with understanding which insects to encourage. For more on chemical-free pest management, see our natural pest control guide. For a broader view of making the garden work for wildlife, the wildlife-friendly garden guide covers birds, mammals and the wider habitat picture.

Pollination is the other major service. Without insects to transfer pollen between flowers, most fruiting crops — tomatoes, courgettes, beans, cucumbers, apples, strawberries — produce poorly or not at all. A garden with abundant pollinators is a garden that crops reliably.

Who the helpers are

Getting to know the main beneficial insects by sight helps you recognise them rather than brushing them away or, worse, mistaking them for pests.

• Ladybirds (ladybugs): the most widely recognised garden predator. Both adults and larvae eat aphids, scale insects and other small pests. The larvae look nothing like the adult — they are small, dark and spiky, often with orange or yellow markings. They are commonly mistaken for something harmful and killed. A single ladybird larva can consume a significant number of aphids during its development. Different species have different spot counts — two-spot, seven-spot, harlequin and many others are all broadly beneficial.
• Lacewings: delicate, pale green flying insects with large, gauzy wings. Adults feed on pollen, nectar and honeydew; it is the larvae that are voracious predators. Lacewing larvae — called "aphid lions" by some — attack aphids, small caterpillars, thrips, whitefly and other soft-bodied pests with considerable efficiency. They overwinter as adults, often in dry shelter — a bundle of hollow stems or a loosely stuffed box of corrugated cardboard is enough.
• Hoverflies: often mistaken for bees or wasps because many species have yellow and black striped abdomens, but they have only two wings (flies) rather than four (bees and wasps), and they hover. Adults are important pollinators, visiting a wide range of flowers for nectar and pollen. Many hoverfly species lay eggs near aphid colonies, and the larvae that hatch are efficient predators, consuming aphids directly. Attracting hoverfly adults with flowers therefore also delivers pest control as a by-product.
• Ground and rove beetles: often overlooked because they are nocturnal and spend most of their time under soil, stones, logs and leaf litter. Ground beetles (family Carabidae) hunt at night, pursuing and eating slugs, cutworms, vine weevil grubs, and other soil-dwelling and surface pests. Some species are large and fast. Rove beetles (family Staphylinidae) are common in compost heaps and soil and perform similar roles. Both need undisturbed ground cover and leaf litter to thrive — a tidy, bare-soil garden provides them with nowhere to live.
• Parasitic wasps: a large and diverse group of small wasps — most are tiny and none of the common garden species sting humans — that lay eggs in or on the bodies of pest insects, including aphids, whitefly, caterpillars and vine weevil. The hatching larvae consume the host from within. Parasitised aphids turn a distinctive papery, mummified colour. Parasitic wasps are particularly well served by umbelliferous flowers, which provide the nectar they need as adults.
• Bees and other pollinators: honeybees, bumblebees, and a wide range of solitary bees (mason bees, mining bees, leafcutter bees and many others) are the primary pollinators for most garden crops and flowering plants. Bumblebees are especially effective for tomatoes — they vibrate the flower at the correct frequency to release pollen (buzz pollination), something honeybees do not do. Solitary bees, which are often overlooked in favour of honeybees, are frequently more efficient pollinators per individual and are essential for orchard fruit.

Plants that attract beneficial insects

The single most effective thing you can do for beneficial insects is grow a wide variety of flowering plants that bloom across a long season — from early spring through to late autumn. A garden that has flowers only in midsummer leaves beneficial insects without food at both ends of the year, when it matters most.

Some plant families are particularly attractive to the broadest range of beneficials:

• Umbellifers — plants with flat-topped clusters of many small flowers — are outstanding. Fennel, dill, angelica, alexanders, cow parsley, sweet cicely, yarrow (Achillea), and the herb coriander (cilantro) left to flower are all excellent. The open, accessible flower structure suits the short tongues of many hoverflies and parasitic wasps. Fennel in particular is one of the most visited plants you can grow.
• The daisy family (Asteraceae) provides accessible, pollen-rich flowers for a huge range of insects. Single-flowered varieties — echinacea, rudbeckia, single dahlias, calendula, cornflowers, ox-eye daisies, single marigolds — are far more useful than double-flowered forms where the nectaries and pollen are hidden inside a mass of extra petals. Calendula (pot marigold) is one of the easiest to grow from seed and one of the most productive insect plants for a long season.
• Borage produces long successions of small blue star-shaped flowers and is extremely popular with bumblebees and honeybees. It self-seeds freely in most gardens, turning a single plant into a reliable annual colony.
• Phacelia is often grown as a green manure but its flowers are outstanding for pollinators — bumblebees in particular show a strong preference for it. The fine-textured blue flowers last for weeks.
• Native wildflowers for your region will typically be more attractive to your local beneficial insect populations than exotic ornamentals, simply because they have co-evolved together. Leaving patches of local wildflowers — or letting grass grow a little longer and not cutting until late summer — makes a significant difference.

Single-flowered varieties are consistently more useful than double ones. Many popular modern garden cultivars have been bred for larger, more spectacular flowers that are effectively useless to insects. When buying plants or seeds, check whether the variety retains its reproductive parts in an accessible form, or look specifically for species-type or "single" varieties.

Avoid the urge to spray

This is perhaps the most important section in the guide, and the one that runs most directly against gardening instinct. When you see an aphid colony on a rose stem or caterpillars on a brassica, the impulse to do something — to spray — is strong. But acting immediately, before beneficial insect populations have had a chance to respond, often makes the situation worse over the medium term.

A more useful approach:

• Observe before acting. Aphid colonies typically peak and then crash as predator populations catch up. A colony that looks alarming in week one is often completely cleaned up by week three without any intervention.
• Intervene physically rather than chemically when you must — squash aphids by hand, pick off caterpillars, use physical barriers. These targeted actions do not harm the wider insect community.
• Tolerate some pest damage. A few holes in a cabbage leaf, a little distortion on a rose tip — these are signs of a living, functioning garden ecosystem. A garden with no pest damage at all is a garden with no food for predators, and therefore no predators.
• Accept that some plants in some years will struggle. This is normal. Growing a diverse range of plants means that no single pest attack defines the whole garden's season.

Water, shelter and undisturbed areas

Flowers bring insects in for food; habitat keeps them in the garden to breed, overwinter and become established populations rather than transient visitors.

• Water: a shallow dish, upturned bin lid or small pond provides drinking water for a wide range of insects. Bees in particular need water — especially in warm weather — and will visit the same sources reliably. Keep a stone or some pebbles in a shallow dish of water so insects can land without drowning. Change the water regularly to prevent mosquito breeding in still water.
• Insect hotels and shelter: bundles of hollow stems (bamboo, dried elder, cut umbellifers), blocks of wood with drilled holes of varying diameters, loosely stacked corrugated cardboard, and bundles of straw all provide overwintering and nesting sites for solitary bees, lacewings and other beneficial insects. Position them in a sheltered, sunny spot facing south or south-east, fixed firmly so they do not move in the wind. Replace hollow stems every couple of years as they degrade.
• Leaf litter and undisturbed ground: ground beetles, rove beetles, slow worms and many other garden allies need somewhere to hide by day and overwinter. A small area of permanent leaf litter, a log pile, a patch of rough grass, a compost heap — all provide this. Resisting the urge to be too tidy makes an enormous difference to the ground-level predator community.
• Reduced mowing: even a narrow strip of longer grass left unmown along a fence or path, allowed to flower and seed before being cut in late summer or autumn, provides habitat and food for a range of insects that a uniform, close-mown lawn does not.

Companion flowers among vegetables

Weaving flowering plants through the vegetable garden rather than keeping them in a separate border makes the connection between beneficial insects and the crops they protect immediate and practical. The hoverfly adult that feeds on your calendula flowers may lay its eggs on the aphid colony attacking your broad beans a few rows away.

Some particularly useful companions for the vegetable garden:

• Calendula (pot marigold): long-flowering, easy from seed, attractive to hoverflies and bumblebees, and itself a mild deterrent to some aphid species.
• Phacelia: can be sown in gaps between crops and provides exceptional pollinator value in a small space.
• Dill and fennel: allowed to flower rather than always harvested for foliage — outstanding for parasitic wasps and hoverflies, and the seeds attract finches in autumn.
• Sweet alyssum (Lobularia maritima): a low-growing annual with masses of tiny white flowers that are highly attractive to hoverflies and parasitic wasps. Useful as a ground-cover companion under taller crops.
• Borage: its flowers are particularly attractive to bumblebees and it self-seeds freely, establishing itself as a reliable annual presence once introduced.

Make a pollinator and beneficial-insect patch

Even a small dedicated area — a metre-square bed, a large pot, or a strip along a path — planted specifically for beneficial insects can make a meaningful difference to the insect life in your garden. Here is how to set one up:

1. Choose a sunny, sheltered spot. Most beneficial insects prefer warmth. A patch that receives direct sun for most of the day will attract more visitors than a shaded one. Even a sunny wall with a container in front of it counts.
2. Plan for a long flowering season. Select plants that flower across spring, summer and autumn rather than all at once. Early flowers — crocus, single hellebores, pussy willow — are valuable when little else is in bloom. Late flowers — ivy, Michaelmas daisies, sedums — carry insects through to overwintering.
3. Include umbellifers and daisies as a priority. Fennel, dill, yarrow or any of the umbellifer family alongside calendula, single marigolds or echinacea gives you the two most valuable plant families for beneficials in one small space.
4. Add a shallow water source nearby. A terracotta saucer with a layer of pebbles and a little water provides immediate drinking access for insects visiting the flowers. Top up regularly in dry weather.
5. Place an insect shelter or hotel close by. A bundle of hollow stems in a south-facing spot, or a small wooden shelter with tubes, allows insects to stay in and near the patch rather than moving on after feeding. Attach it securely so it does not swing in the wind, which discourages use.
6. Avoid all pesticides on and around the patch. This is the non-negotiable element. A single application of insecticide can undo the insect community built up over a season. Leave the patch — and ideally the surrounding garden — entirely chemical-free.
7. Leave some end-of-season seedheads standing. Do not cut everything back cleanly in autumn. Hollow stems and seedheads provide overwintering habitat for lacewings and other insects. Cut back in late winter or early spring when new growth is appearing, not before.

• At least one umbellifer (fennel, dill, yarrow, angelica) in flower somewhere in the garden.
• At least one daisy-family plant with accessible, single flowers (calendula, echinacea, rudbeckia).
• Flowers present from early spring through to late autumn — plan for gaps and fill them.
• Shallow water dish with pebbles, topped up regularly.
• Some undisturbed leaf litter, log pile or rough grass for ground-level habitat.
• Insect shelter or bundle of hollow stems in a sheltered, sunny, south-facing position.
• No pesticides used on or near the flowering area.
• End-of-season seedheads and stems left standing until late winter.