Introduction
With a diverse combination of plants, gardens can provide richer habitats for wildlife and biodiversity than many found in nature. No matter how you use your garden, it provides a habitat for wildlife. You don't need a wilderness to attract wildlife, close observation and a good appreciation of the value of garden spaces for wildlife can make a real difference.
Moths and Butterflies
Adult moths and butterflies not only add interest to the garden, they and their larvae also provide a food source for other wildlife including birds, mammals and other insects.
There are many different types of moth and butterfly, that as larvae often feed on the foliage of specific plants and as adults feed on nectar from a wider range of flowers.
Adults of some of the largest and most colourful butterflies, including red admirals and small tortoiseshell, are often seen on asters and buddlejas. The smaller holly blue butterfly adults tend to feed on the flowers of ivy and holly, while the spring brood of their caterpillars feeds on holly, and the summer brood feeds on ivy.
Different species will often use cracks and crevices, such as hollow stems or bark fissures, for shelter to hibernate over-winter as either adults, eggs, larvae or chrysalises.
Bees and Bumblebees
Bees are essential pollinators for most plants, other than those that are wind pollinated.
There are several different species of bumblebee, which have thicker, hairier, bodies than honeybees. They forage for food and pollinate flowers but, unlike honeybees, the colonies in which they live do not survive the winter, leaving only the young queens hibernating underground.
Honeybees live in organised colonies, collecting pollen and nectar to feed to their developing larvae. Surplus honey is stored for food during the winter months.
Many solitary bees are also beneficial to the garden as pollinators. Many species are capable of making their own nests, in excavated hollows in sandy soil or mud nests, but some species require existing holes in hollow plant stems or beetle emergence holes in dead wood.
Hoverflies and Ladybirds
There are many different types of ladybirds and hoverflies, some of which are great aphid-eaters.
Hoverflies get their name from their habit of hovering over plants before landing to gather pollen and nectar. They prefer flowers with exposed pollen and nectar, such as daisy-type flowers, so they can easily reach it with their short mouthparts. It is the hoverfly larvae that are most useful to the gardener, as they will eat several hundred aphids before they are ready to pupate into adults.
Many adult ladybirds and their larvae are voracious aphid-eaters. The adults lay their eggs on aphid-infested plants so when their larvae emerge there is an ample food supply. Some other ladybirds and their larvae are specialist feeders on scale insects, red spider mites or powdery mildews. In cold weather adult ladybirds hibernate, searching out cracks in bark and hollow stems where many hundreds will congregate to spend the winter.
Birds and Mammals
Many birds and mammals make full use of gardens, eating insects, seeds and fruits and using plants for nest material and for nesting and hibernation sites.
Birds such as blue tits, and blackbirds are omnivores, feeding on a wide range of different foods, though others are more discriminating. Insect-feeders, such as swallows and house martins, catch insects on the wing while wrens, and chiffchaffs collect insects directly from the plants on which the insects are feeding. The diets of some birds consist mainly of seeds and fruit. Goldfinches and tree sparrows feed only on seeds while fruit and berry-eating birds include redwings and blackbirds.
Mammals such as hedgehogs often use gardens, both as a place to find food such as worms and slugs but also as shelter to hibernate in leaf or log piles at the base of hedges or shrubs. Seeds and berries will also provide food for harvest mice and dormice.
Trees and Shrubs
Many trees and shrubs provide shelter and homes for wildlife; the most useful also provide food as foliage, nectar, pollen and/or fruit.
Small trees, including hawthorn and birch, are valuable to insects, birds and other animals. Dead wood and tree rot holes can also be important habitats for insects, especially some beetles and flies.
Shrubs provide shelter for birds enabling them to roost and nest safely. Some, such as Cotoneaster and Pyracantha, also provide berries. Climbers, including honeysuckle (which is the favoured nesting material of the dormouse) and ivy, are attractive to birds while ivy is valuable for bearing fruit and flowers for winter food.
Dense hedges provide windbreaks and shelter to the garden. The dense branches provide cover for small mammals, spiders, bees and other insects, along with nesting and roosting sites for many birds.
Herbaceous perennials
Flower beds and borders containing mixed herbaceous perennials can provide plenty of food for wildlife, act as a refuge for attractive wild flowers and offer shelter to insects, birds and small mammals.
The nectar and pollen produced by flowers supports a wide range of flower-visiting insects. These insects in turn support a wide range of insectivores, including other insects, birds and small mammals. Seed heads are also a good source of food for birds, and are an important source of food through autumn and into the winter.
Flowering plants in full sun will attract the maximum number of bees, butterflies and other insects. Single-flowered plants are of most benefit because the design of these blooms makes it easier for insects to reach the nectar and pollen.
Water
While many birds and mammals will visit ponds to drink or bathe, insects and other invertebrates will use ponds as a breeding site or a hunting ground. This will in turn attract more wildlife such as bats and birds that will visit to feed.
Ponds are the breeding sites for all amphibians (frogs, toads and newts). Fish add interest to a pond but it should be noted that they eat large quantities of tadpoles and aquatic insects.
Ponds are essential to dragonflies and damselflies as they lay their eggs just below the surface of the water. The larvae spend between 2 and 5 years in the pond before climbing out of the water to shed their skin and emerge as adult insects. The adults feed on midges by swooping over water to catch them in flight.
Grass
Close mown turf is a good hunting ground for birds and a few mammals, seeking worms and soil dwelling insects such as leatherjackets, chafer grubs and ants.
Meadows and long turf are important habitats for several butterflies such as the common blue, which lays it eggs on the leaves of bird's foot trefoil (Lotus corniculatus), and the larvae of the meadow brown and small skipper butterflies which feed on soft grasses. In general a minimum of 6 native grass species is recommended for moths and butterflies.
Long grass also provides a habitat for many small insects, which in turn provides food for insectivores such as bats, frogs, toads, dragonflies and birds such as swallows and wagtails.
Meadow flowers such as buttercups, ox-eye daisy, meadow geranium and thistles provide nectar and pollen for a succession of bees, butterflies, hoverflies and other insects.
Plant Selection
Having variety within the garden provides the greatest number of options for wildlife, as different species choose different things to eat, and places to rest or reproduce.
Plants with nectar-rich flowers will provide a valuable food source and they are best placed in full sun to attract the maximum number of bees, butterflies and other insects. Single-flowered plants are of most benefit because the design of these blooms makes it easier for insects to reach the nectar and pollen. Many double flowers are inaccessible to insects or have low amounts of nectar and pollen, or none at all.
Although many insects are not active in winter, some will still seek nectar late into the autumn and a warm spring day will encourage many to become active. Having a selection of plants flowering throughout the year can help ensure there are always some nectar sources available.
Timing
Having a variety of plants and designed features within the garden encourages and benefits wildlife. However, much of the benefit could be lost if some consideration is not given to the effects of gardening practices.
Consideration is often given for nesting birds, with hedges cut back after the breeding season, or to amphibians with care taken when clearing marginal plantings. However, small actions, such as leaving seed heads in the autumn, providing a source of food late into the year, can also be of significant worth.
Gardening has a natural, seasonal rhythm of regular practices such as planting, pruning and mowing. Creating a stable balance within the garden environment is naturally better than constant, or rapidly fluctuating, change.