Sometimes when you’re trying to make your outdoor space more wildlife-friendly it’s not so much what you do, as what you don’t do, that makes all the difference.
Take tidying up, for example. As the days get longer, it’s tempting to get outside to cut back dead stems – but doing this too early could destroy the homes of hibernating beneficial insects, like ladybirds and lacewings. Try to wait until April if you can – by then, insects should be out of hibernation, and less at risk of succumbing to snaps of severe cold weather.
Burning bonfires should be avoided at all times of the year. If you have space, pile up branches and twigs in a quiet corner. This type of habitat is fantastic for all sorts of invertebrates, as well as hedgehogs, toads and slow worms.
Be careful when trimming hedges too. Wild birds in the UK have legal protection – and this includes their nests and eggs. Hedge cutting shouldn’t be done at all between 1 March and 31 July, as it’s illegal to cut hedgerows during nesting season.
But care should be taken when cutting hedges at any time of year, to avoid destroying a vital habitat for birds and pollinating insects. Mixed native hedgerows provide an important source of natural food for all sorts of creatures, with nectar-rich blossoms in spring and berries in autumn. Ideally, trimming should be done once a year, in winter, after most of the berries have been taken and before the blossoms begin to bloom.
The RSPB has more detailed advice on maintaining wildlife hedges at www.rspb.org.uk/birds-and-wildlife/ advice/gardening-for-wildlife/plants-for-wildlife/garden-hedges/.
Here are three more things to avoid if you want to boost biodiversity in your garden, allotment or community green space.
Weedkillers don’t know the difference between a ‘weed’ and a wildflower – they will kill all plants they come into contact with. The dangerous chemicals they contain leach into the soil and end up in water sources, harming earthworms and aquatic creatures.
University of Birmingham research showed that prolonged exposure to glyphosate-containing weedkillers causes significant harm to keystone species. The study examined the effects of the weedkiller on daphnia (waterfleas) – an important species at the heart of aquatic food webs, that can be used to assess environmental impacts on ecosystems.
The findings showed that – even at recommended ‘safe’ concentrations – the weedkiller caused embryonic development failure and DNA damage, and it interfered with the animals’ metabolism and gut function.
Many so-called ‘weeds’ are in fact wild plants that are immensely beneficial to all sorts of wildlife. Dandelions, for example, are often targeted with weedkiller by people who want things ‘neat and tidy’ – but the flowers support more than 50 insect species (which in turn feed other insect-eating animals). And dandelion seeds are a food source for birds such as goldfinches. So killing off these valuable plants reduces the natural food sources available to all sorts of creatures.
Where wild plants are growing in places where you really don’t want them – for example, a vegetable garden – they can be controlled or removed with non-toxic methods such as hoeing, mulching or digging. Large areas can be covered with carboard to suppress and weaken unwanted weeds by blocking out light.
Pesticides are harmful to all insects, including important pollinators such as bees. Pesticide residues in soil are toxic to soil-living organisms, and residues in insects and worms move up through the food chain to harm birds and mammals.
Friends of the Earth’s Problems with Pesticides report cites numerous studies that have found links between pesticide use and wildlife population declines. These include a long-term study finding declines in 15 butterfly species in areas of high pesticide use, and declines in common blue‐tailed damselflies, linked to neonicotinoids.
Pesticides also find their way into our rivers. In a UK study, 88% of water samples from rivers and other freshwater habitats in England showed pesticide contamination, with half of the samples tested exceeding chronic pollution limits.
Insect declines have a massive impact on the creatures that depend on them for food. Hedgehogs, for example, are struggling for various reasons including a lack of insects to eat – linked to use of pesticides and slug pellets in gardening.
To keep pest populations in check without pesticides, attract insect-eating birds to your garden with feeders. Also provide natural food sources such as berry-producing plants, as well as nesting sites, shelter and water. Garden birds are fantastic allies in the garden: blue tits, for example, feed on aphids, and thrushes eat snails.
You can also attract beneficial insects with nectar-rich planting, wildflowers and areas of long grass. Ladybirds and hoverflies eat pests such as aphids and whiteflies. Hoverflies are also important pollinators, and many species particularly like yellow or yellow-centred flowers – so grow calendula, cosmos and fennel, and let dandelions grow, to attract them.
Healthy peatlands are home to all sorts of special plants, insects and birds – some of which are found nowhere else.
Taking thousands of years to form, peatlands are also the most efficient carbon sinks on Earth – storing more carbon than any other habitat on land, including the world's rainforests. They soak up rainwater – reducing the risk of flooding – and act as a filter to improve water quality.
Commercial extraction of peat has a massive ecological impact, removing over 500 years-worth of 'growth' in a single year. So, to protect these precious wild places, buy peat-free compost.
The UK government is taking steps in the right direction, by banning sales of peat for amateur gardeners in England from 2024. But in 2023, there is still a choice – so please choose peat-free! Beyond 2024, although amateur gardeners will no longer be able to buy bagged peat in England, as yet there are no plans for a ban for the professional horticulture sector until at least 2028.
This means that plants you buy may still be grown and potted up in peat-based compost. Ask your local garden centre or other retailers how their plants are grown. There are lots of nurseries and smaller professional growers who are committed to being peat-free – so seek these out, and support them!