What good are these ‘pests’ doing for your garden?
It can be easy to dismiss some garden occupants as pests with no redeeming qualities, but in the complex ecosystems of our gardens there are benefits to many of our least welcome guests.
Wasps
When we think of wasps we generally think of the social wasps that turn up and annoy us at late summer picnics. Social wasps account for only a few of the UK’s wasp species – the other 7,000+ are solitary or parasitic wasps. Wasps help out gardeners by controlling pests, with larvae feeding on aphids, flies and caterpillars, and parasitic wasps laying their eggs inside their prey. Some adult wasps are also pollinators.
Slugs
Some slugs may put a dent in your prize veg, but slugs are also important detritivores, eating and breaking down decaying organic matter like dead plants. This adds to the organic matter content of your soil, adding nutrients and helping improve soil structure for better water retention and drainage. Slugs are also a food source for some of our favourite garden wildlife, including frogs, hedgehogs, slow worms and blackbirds.
Need to reduce the damage? The are plenty of non-chemical options – avoid slug pellets which can harm animals higher up the food chain. Instead try beer traps, nematodes (microscopic worms that kill slugs and can be bought and watered into the soil), and nightly slug patrols to remove them by hand.
Caterpillars
It’s primary school biology – if you want beautiful, pollinating butterflies and moths you need leaf-hungry caterpillars. Caterpillars are also a key food source for many small birds like blue tits, and declining numbers of butterflies and moths is negatively impacting these animals. As well as having butterfly friendly plants like Buddleja in the garden, we also need caterpillar food plants. Caterpillars are generally specialist feeders so different species need different food plants, but some good ones to include in the garden are Nasturtiums (Tropaeolum majus), Hawthorn (Crataegus monogyna), bird’s foot trefoil (Lotus corniculatus) and, if you have space for an area that can be left to go a bit wild, nettles (Urtica dioica).
Need to reduce the damage? Some of the most common caterpillars that will cause issues in the veg garden are cabbage caterpillars (large white, small white and cabbage moth). Fine netting can be used to protect brassicas at risk so adults can’t lay eggs, and inspecting the plants regularly to remove eggs and caterpillars can help.