Benefits of Wildlife in the Garden: Natural Pest Control and Ecological Balance

Benefits of Wildlife in the Garden: Embracing Ecological Subsystems

Pest Subsystems: Pests as Resources

Pests are essential to ecology and a resource for others. They're only pests when eating our crops; otherwise they're wildlife, recyclers, pollinators. Woodworm in a dead log recycles; in a tree, post, or table it's a pest. Some pests are friends—thrips and capsid bugs damage plants but eat spider mites.

Plants in nature balance with pests. Monocultures or eliminating natural controls cause rampages. Healthy, well-growing plants suffer little harm—most we grow are remarkably trouble-free. Key pests concern a few susceptible vegetables/fruits. We aim to control, not eliminate—some pests must survive to keep predators alive; without predators, new pests escalate. No snails means fewer songbirds; even snails consume diseased/wilted material.

Predator Subsystems: Natural Pest Control

In natural food webs, predators eat prey. Garden predators are largely beneficial, eating pests and controlling numbers. Predators and parasites in a stable ecosystem need pests to survive. Left alone, they control pests effectively in a complex web where they prey on pests and each other—especially larger predators (hedgehogs, birds) which eat almost anything, friend or foe.

Ladybirds are famous predators, but almost all beetles eat slugs and small pests/eggs. Spiders—all predatory, millions in a large healthy garden. Hoverflies, lacewings, anthocorid bugs, wasps control spider mites, aphids, caterpillars. Parasites: chalcids, ichneumon flies, minute wasps live on/in hosts.

Predators breed slower than pests—usually no issue as other factors limit pests. But pesticides killing predators along with pests cause pest resurgence. Rebuilding a complex self-regulating system takes years. Avoid all pesticides, even organic-approved. Grow diverse plants—especially sacrificial plants (honeysuckles, sweet cherries, nettles, lupins) that host pests with little detriment—to maintain background predator levels controlling pests elsewhere. Ground-cover plants, rough grass strips support walking predators (beetles). Provide nectar/pollen for flying predators (plants featured in bold below).

Pollinator Subsystems

Bees are best-known pollinators, but hoverflies, flies, butterflies, beetles, wasps also transfer pollen. Bumblebees crucial for early-flowering plants (fly in cooler weather). Can be bought in cardboard huts for greenhouses. Main requirement: more flowers, flowering through the longest season.

Recycler Subsystems: The Largest Workforce

Most small creatures recycle material from larger forms. Woodlice kill young caterpillars. Larger creatures recycle by foraging/disturbing litter, pecking rotten logs for grubs. Pollinators recycle pollen/nectar as more pollinators; their bodies add to soil fertility. A honeybee colony (30,000–100,000 bees) loses up to 10,000 bees/week in summer. Insect bodies rich in chitin benefit soil/plant health.

We are all recyclers. Plants build from air, light, water, nutrients from decomposing organic matter. Faster turnover and more life forms = more garden support. Most recyclers live on/near soil surface. Without them, corpses would accumulate. They convert dead/diseased material into plant food—fastest in aerated, warm, moist conditions under groundcover, leaves, mulch. Duplicate these conditions, supply organic material, they'll convert it to fertility.

But predators eat recyclers too—provide refuges. Small piles of rotting logs, rocks, bricks, bottles hidden under hedges/evergreens. Snails (often pests) congregate there—use as collection points.

Key Beneficial Groups and Their Plants

Butterflies—often pests in disguise but usually useful pollinators; beauty alone warrants encouragement. Buddleia, Sedum spectabile, golden rod, valerian, lavender attract them. Also: Dianthus, Hesperis, honeysuckle, hyssop, lilac, Lychnis, Lythrum, Myosotis, Origanum, Viola. Many yellow/orange/red flowers. Night-scented flowers appeal to moths.

Bees—many species threatened by wildflower loss. Each gardener can help with a few bee plants—short-term fruit pollination, long-term survival. Bumblebees and leaf-cutter bees more valuable than honeybees (fly colder, pollinate earlier). All need continuous pollen/nectar—grow many flowers to spread season. Bumblebees need early spring: Aubrieta, Berberis, bluebells, dandelions, flowering currants, wallflowers, white dead nettle. Early summer: brambles, buddleia, clover, comfrey, Cotoneaster, Fuchsia, globe artichoke, golden rod, jasmine, knapweed, lavender, mallow, Michaelmas daisy, raspberry, rhododendron, thistle, vetch.

Hoverflies—best aphid eaters. Larvae eat up to an aphid/minute! Adults attracted to yellow flowers: broom (favorite aphid host), yarrow, knapweed. Best plant: Limnanthes douglasii (poached egg flower)—low, self-sowing annual, grows anywhere, fills garden with hoverflies and bees. Buckwheat and Convolvulus tricolor for late nectar. Most flowers benefit hoverflies: Alyssum, Arabis, Aubrieta, cornflower, Cosmos, Eschscholzia, Geranium (not Pelargonium), golden rod, grape hyacinth, heliotrope, honesty, Iberis, all marigolds, Michaelmas daisy, Nemophila, Nicotiana, Petunia, Phlox, all poppies, Rudbeckia, Sedum spectabile, Shasta daisy, stocks, sunflower, sweet rocket, sweet William, Wivelsfield, tansy, all mints, wallflowers. Letting celery/carrots go to seed encourages hoverflies and beneficial insects.

Ladybird and lacewing adults take nectar/pollen from hoverfly plants but also like Allium, Anthemis (dill), fennel, yarrow. Lacewings fed only aphids didn't lay eggs—best encouragement is plenty of tempting food. Grow aphid-laden plants (nettle patches, honeysuckle, lupins, sweet cherries) for healthy predator/parasite background. Overwintering adults hibernate in conifers, evergreen hedges, dense culinary herbs. Nest boxes from hollow stems help—hide in dry places.

Wasps—friends most of year, eating pests spring/summer; autumn they eat fruit. Dead rotting wood provides nest material. Nectar plants for hoverflies encourage wasps; more importantly benefit predatory wasps parasitizing caterpillars, beetles, aphids, spiders.

Spiders—all friends, sensitive to pesticides. Encourage with right habitat: strings for webs in convenient places, water, hollow stem bundles for nests.

Beetles—large group; most (ladybirds) friends, exceptions (wood-borers). Good pollinators in cold/wet when others can't fly. Thick groundcover hides ground-dwelling beetles from predators. Dense foliage collecting dew doubly useful. Plants with hiding places between leaves, under rough bark, in congested twigs, deadwood hide/hibernate beetles.

Frogs, toads, newts—eat many pests, need water/wet places. Keener to patrol with good groundcover, preferably moist underneath. Lush, moist overgrown greenhouse corner hosts frogs/toads. Newts equally useful, fascinating mating dance. My polytunnel abuts pond with low log wall for access—friends come in to eat pests. Generally, newts and frogs won't breed in same small pond—consider two small ponds if space allows.

Birds—gardeners often want to remove, but overall beneficial. Exceptions: pigeons, magpies, seagulls. Most are hungry friends eating pests—control more than they spoil. Individual crops may need protection, but we benefit from more birds. Attract with habitat, reliable food, water (essential). They appreciate a bath safe from cats.

Grow fruit—birds prefer cultivated over wild. Redcurrants, cherries disappear fast; few fruits survive winter. Berries equally appreciated; yellow ones confuse briefly then vanish. Provide water to reduce damage. More fruit = less damage per plant—plant sacrificial berrying trees/shrubs. Seeding plants (sunflowers, wheat) attract/feed; save some heads for winter.

Dense hedges, evergreens, climbers favor birds—nooks for nests/shelter. Wild nest sites rare—provide nest boxes. Encourage useful birds: blue tits, great tits, tree sparrows, small insectivores. Ideal nest site: old woodpecker hole (always preferred). Inside shape matters more than outside—deep rounded bowl best (papier-mâché insert). Robins, flycatchers, wagtails prefer wider, open-front boxes. Boxes should resemble natural holes, fixed to trees safe from cats. Place where watchable from window, except robins—boxes hidden in shrubs/hedges. Blackbirds, thrushes find sites in dense evergreens/thick hedges. Bend branches down, tie for nesting platforms, or prune hard for splayed shoot clusters.

Swallows, house martins bind nests with mud—shortage as garden ponds lack muddy edges. Fewer strawy dung piles, livestock hair on hedges deprives house martins. Mud-only nests fall off when baked/shrunk. Hang hair trimmings, put mud bowls by pool for these insect eaters.

Worms—if you want songbirds, you need worms! Most important garden creatures. Excrete 30+ tons casts/acre/year—best soil texturizer/fertilizer. Casts water-stable (prevent mud), granular texture promotes root growth. Burrows aerate/drain; abandoned burrows followed by roots for nutrient lining. Digestion reduces mineral particles, aiding micro-organisms. Encourage worms by keeping soil moist and mulched.

I feed bare soil and mulched areas monthly with grass clippings—they need 'greens' plus organic matter (compost, well-rotted manure). Multiply with ground seaweed, blood/fish/bone meal, hoof/horn meal. Avoid rotary cultivation; dig minimally by hand—both kill worms. Acid soils: add lime every 4 years unless lime-hating plants. Lime keeps soil sweet, feeds worms, ensuring efficient drainage, aeration, recycling.

Hedgehogs—friends, but don't thrive on milk/bread—dog/cat food better. Plant dense shrubs with dry centers for hibernation. Hedgehog boxes under shrubs/hedges: waterproof, ≥1 ft³, fist-sized entrance, stuffed with dry leaves/hay/shredded newspaper.

Bats—eat tremendous flying pests. Encourage with roosting and hibernating sites. Roosts: flat wooden boxes open underneath, attached high on warm walls. Hibernation sites harder. Some trees (limes with aphid crops) shower aphids in breeze, attracting bats.