How productive gardening can help wildlife (and measures large scale producers are taking)
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By Judith Conroy, Wildlife Gardening Forum Trustee
Researcher, Coventry University's Centre for Agroecology, Water and Resilience (CAWR)
The UK's gardens are a significant habitat, forming a network of green spaces through towns and cities, and there are measures gardeners can take to nurture wildlife on their own a little piece of the natural world. Most gardeners who produce their own fruit and vegetables will aim to grow a wide variety of crops, so the productive garden is normally diverse; a wide range of vegetables, flowers, trees and bushes, compost heaps and other areas, results in a patchwork of spaces for wildlife – a polyculture.
Fruit trees and bushes such as apples, plums, blackcurrants and gooseberries flower at an important time of year, providing an early source of pollen and nectar for insects such as bees and hoverflies. As most gardeners will not manage to pick every single fruit from a mature, productive tree, these can be an important food source for birds in autumn and early winter. Trees and bushes can be under sown to provide further flowers though the summer: seed mixes can enhance grassy areas under trees and below fruit bushes, low growing species such as clovers and poached egg plant (Limnanthes douglasii) can provide a ground cover of flowers.
Compost heaps can be a habitat all of their own and gardeners who grow fruit and vegetables have an added incentive to make compost to boost their productivity. Compost heaps can be home to a whole range of garden wildlife including slow worms, beetles, centipedes and countless microscopic life. Having different heaps at different stages of decomposition means even more variety. Making compost also reduces reliance on external inputs and the wider environmental footprint of their production and transportation. Depending on the size of plot, gardeners may choose to let woody wastes such a fruit tree prunings rot down in their own heaps, creating a further type of habitat that will be colonised by insects, amphibians and fungi.
Crops like peas, beans, pumpkins, squash and tomatoes all produce flowers but many gardeners will grow other flowers among vegetables specifically to attract insects; not just for pollinators but to draw in predators such as hoverflies and wasps which control crop pests, particularly aphids and help enable natural balance.
- Edible flowers such as calendula, borage and nasturtium add interest to salads but also increase diversity in the vegetable patch.
- Most commonly grown herbs such as chives, thyme, oregano and lavender are excellent sources of forage for bees, flies and other insects.
- A lot of vegetable plants are biennial, producing seed in their second year, so by leaving a couple of parsnips or rocket plants un-harvested, gardeners can add extra floral diversity. Flowers in the carrot family are particularly good at attracting tiny parasitoid wasps that prey on aphids.
Many productive gardeners grow green manures (cover crops) to improve and protect the soil, whilst suppressing weeds in temporarily bare plots*. Many green manures produce flowers including phacelia, vetch and mustard which are visited by insects. Some green manures can be used to cover/protect soil beneath a growing crop. For example, clover grown under pumpkins or squash will provide a carpet of flowers. The roots of these crops also creates a stable environment for soil fauna in the upper layers and provide cover for above ground dwelling species such as beetles.
As well as actions within the productive plot that benefit wildlife, there are choices gardeners can make about wider issues beyond the garden gate. A current hot topic is the use of peat in growing media. Mining peat is a devastating process which denudes rare habitat, (and impedes its roles as a carbon sink and in flood water attenuation). Consistent, high-quality peat-free growing media has been available to gardeners for some time and several large organisations operating gardens open to the public have chosen to eschew peat for several years now.
Allotments and smaller field scale systems (such as Community Supported Agriculture schemes) have similar wildlife benefits to gardens but at a larger scale, it can be more difficult. Even in certified organic production where ecological principles are observed, monocultures may still exist on bigger farms. There are, however, an increasing number of larger growers adopting agroecological methods, where the principles of ecology are applied to farming. Agroforestry is increasingly used, often in the form of ‘alley cropping’ where rows of productive trees are grown with cereal and vegetable crops in between. Many farmers concerned about wildlife and the overall health of the ecosystem participate in agri-environment schemes, where they receive financial support to farm in a way that is more supportive of biodiversity. Some also engage in wildlife monitoring or allow surveys of their land to better understand the state of the ecosystem.
Increasingly, food producers are actively engaged in researching how their land could be better for wildlife. There are schemes such as the Soil Association’s Innovative Farmers, a farmer-led research programme for both conventional and organically certified growers - current trials include one to improve soil management to benefit earthworms and another is examining silvopasture, where trees are integrated with livestock to bring positive impacts to biodiversity, soil health and animal behaviour.
Gardens can be both productive and havens for wildlife. It is important to understand the interactions between the different plants and animals that live there – sitting quietly to observe natural processes can reveal a lot about the life that shares our plots - from tiny soil organisms to more conspicuous birds and hedgehogs, every creature plays a part. By allowing as many species as possible to thrive, we can help enable a natural equilibrium that will contribute to the health of our crops. This is easier at a smaller scale where the stakes are not so high but by examining ecological processes, larger scale growers are increasingly finding innovative ways of working in harmony with wildlife.
* Green manures build soil fertility by taking up nutrients that would otherwise leach away, particularly in winter. They are then hoed off or dug in to return nutrients and organic matter to the soil. Whilst growing, they protect the earth from the physical effects of weather and if they are legumes, they will also fix nitrogen.
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