As wildlife gardeners we aim to avoid using pesticides, herbicides and fertilizers as these can harm the ecosystem of our gardens, including the soil ecosystem. We want to work with nature rather than fighting it to keep both the soil and our plants healthy and the biological communities in balance.
Encouraging beneficial insects as predators instead of pesticides
This is a quote from Stephanie Hafferty, an organic gardener and a proponent of no-dig:
“Wildlife gardening and biodiversity is a key part of my gardening. I create wild edges with a wide range of habitats, flowers and other plants. This encourages bees, hoverflies, moths, bats, birds, wasps and other creatures to live in my garden. Many are beneficial predators of pests. I do not use any pesticides, instead the wild life – in particular predatory wasps – help to keep the populations of aphids and other bugs under control. It makes my garden an interesting and companionable place to be too – there’s always something to observe. I also use some crop protections, carefully secured down, including butterfly netting and enviromesh over some of my vegetables, especially the brassicas.”
Another alternative to pesticides is Biological control – the use of natural enemies to control ‘pests’. In the garden this involves introducing predators or pathogenic nematodes. These are a good choice for reducing the numbers of greenhouse pests and vine weevils. At Yeo Valley they use Defenders.
Slugs and slug pellets
As Wildlife gardeners we may think using organic slug pellets is a good method of control. However using pellets, collecting the slugs and snails and throwing them over the garden fence or even mowing them on a damp night (as heard on Gardeners Question Time some years ago) upsets the population of slugs leading to an explosion in numbers.
“The rate of growth of juveniles is inhibited by a substance that they encounter in the slimy trails of the adults. This is a mechanism to prevent overcrowding, but, if the adult population abruptly drops, and the network of slime is reduced, the juveniles are free to start maturing. If the adult snails are suddenly removed, a mob of voracious youngsters will feed furiously to grow up and replace them.” Garden snails by Robert Burton in The Garden April 1995.
It also removes a valuable food source for other species higher up the food chain. As Chris Packham says: “Stop killing your garden slugs”.
“If you make draconian choices like ‘I don’t want slugs and snails to eat my plants’, then you’re doing yourself out of hedgehogs, slow worms and song thrushes and that’s a tragic loss to the garden. The song of the thrush is the closest you’re going to get to a nightingale in the 21st- century British garden.” Chris Packham
So assuming we are not killing them, we could try some of the barrier methods to protect our plants although in an RHS trial they were not particularly successful. Slugs and snails (and soil living slugs in particular) seem to eat plants just as they germinate and emerge from the ground. Rather than direct sowing we can raise our plants in cell trays and only plant them out when they have grown on sufficiently so that they are bigger with tougher, less palatable leaves.