Annuals
Alyssum - Attracts hoverflies and parasitic wasps
Basil - Flowers will attract bees and other insects, it's aromatic foliage is said to repel aphids.
Cosmos - Attracts lacewings and hoverflies.
Dill - Flowers attract lacewings, ladybirds, hoverflies and butterflies.
Marigold - Attracts butterflies and hoverflies, roots produce a secretion that kills root eating nematodes.
Poached egg plant - Great for attracting hoverflies
Sunflower - Bees go mad for these and the birds love to eat the seeds in Autumn.
Perennials
Blackberry - Very good for birds, provides excellent nectar for butterflies and bees, berries attract mammals.
Broom - Good provider of nectar for bees.
Buddleia - A valuable nectar source for butterflies and bumblebees.
Chives - Attracts bees and butterflies.
Fennel - Lacewings, ladybirds, hoverflies and butterflies love this plant.
Garlic chives - Attracts bees, butterflies and other beneficial insects. a good companion plant for roses as the smell repels aphids.
Honeysuckle - The flowers attract night flying moths and the berries are a good food source for birds in Autumn.
Jasmine - Attracts bees by day and the strong beautiful scent attracts moths at night.
Lavender - Bumble bees adore this plant, also attracts hoverflies and butterflies.
Sage - Attracts bees and butterflies.
Speedwell - Attracts ladybirds and hoverflies.
Stinging nettles - An excellent food source for the larvae of butterflies, such as the Red Admiral, Comma and Peacock varieties.
Teasel - Provides a winter food source for finches and its flowers provide a good nectar source for butterflies. Especially good for bumblebees.
Thistle - The Seed heads are loved by all kinds of finches, especially gold finches.
Thyme - Attracts bee’s hoverflies and many more.
Trees and Shrubs
Alder - Seeds attract finches, siskins and all types of tits.
Ash - The seeds are a good food source for bull finches.
Beech - The seeds are a food source for small mammals such as mice and voles and birds such as the chaffinch. It also provides food for some species of moth larvae.
Blackthorn - The flowers provide nectar for spring butterflies and the sloes are a good Autumn food source for many animals.
Cherry(wild) - The fruits are eaten by many bird species.
Crab-apple - It's fruits are a good food source for birds and small mammals.
Dogwood - A good source of food for birds.
Elder - An excellent plant attracting many insects, especially hoverflies it's berries provide food for many birds
Field Maple - A good nectar source for bees.
Hawthorn - The berries are a vital winter food for birds and it supports many insect species. Provides important nectar early in the year.
Hazel - Hazel nuts are a good source of food for many mammals and birds, its foliage provides food for moths and other insects.
Oak - Mature oak trees can support a huge number of insect species which provide good habitats for insect eating birds, such as tree creepers, woodpeckers and nuthatches. The acorns provide food for small mammals.