South Gloucestershire Council - Wildlife Friendly Gardening: Tips from Allotment Holders
In January 2023, South Gloucestershire Council and The Natural History Consortium delivered three workshops for allotment holders on wildlife friendly gardening. These aimed to support allotment holders to garden without using chemical pesticides and encourage more wildlife and pollinators.
Thank you to everyone that came along and shared their gardening tips and advice on alternatives to chemical pesticides. We have created this document to share the most frequently mentioned tips and suggestions from these discussions.
Allotment holders most challenging “pests”
Here were some of the most challenging “pests” with the reasons they were frequently mentioned:
● Slugs/snails - eating young and tender plants, particularly brassicas, lettuces, sunflowers, brassicas.
● Pigeons - eating seeds/leaves/fruits/damaging plants.
● Bindweed was mentioned as a key ‘weed’ - They are fast growing and hard to get rid of.
● Rats – don’t seem to cause particular issues on the actual allotment but they are an issue for adjacent properties. Concerns were raised that rat bait stations are not safe for other small animals e.g., hedgehogs and bait being pulled out of the station.
● Blackfly/whitefly - damaging crops.
A word cloud showing the types of “pests” that were discussed. The larger the word, the more frequently it was as suggested as a top pest.
Top solutions and tips
Before looking for a wildlife friendly pest “solution”, it is key to know exactly what species that is causing a problem, so you can start to try and find the best solution. The free iNaturalist smartphone app is a useful tool to help you identify your species. The app is very user friendly - but if you need a hand, we’ve made a helpful guide on how to use the app.
Knowing about a species can help you to understand its role in the ecosystem. This can also help ensure that you’re not trying to get rid of something that may in fact be beneficial to your allotment system. For example, wasps are not the most popular of creatures. However, with 9000 known species in the UK, these predatory insects are invaluable when it comes to controlling pest numbers and will collect many soft-bodied insects, including caterpillars and aphids, to feed to their larvae. This makes them very beneficial in an allotment system!
Here are some of the wildlife friendly tips to reduce the top “pests” shared at the allotment workshops.
Slugs and snails
● Create a wildlife pond. This will allow frogs, toads and newts to survive in close proximity to your plot and eat your slugs and snails.
● Protect your small, vulnerable crops. This could mean growing them inside or covering them with a barrier such as a cloche (or half a plastic bottle), until they are bigger and more able to withstand damage from slugs.
● Make space for predators; blackbirds, thrushes and starlings will eat slugs and snails. You can encourage more birds by planting hedges and bushes which allow them to thrive. If you’re limited on space, this could be ideal for the communal areas of your allotment where you can also add a hedgehog “house” and bug hotels. You can also support hedgehogs with log piles, long grass & dead hedges, and by making sure there is a “hedgehog highway” (a hedgehog-sized gap in the fence) to allow hedgehogs to get in and out of the allotment.
● Some slug damage is inevitable; so its good to grow slightly more than you need so you still have some crops left after some damage by slugs.
● Create a physical barrier until the plant is large enough to withstand birds pecking. However, if using netting, please make sure it is high quality, with small holes (if you can put your finger through the holes, wildlife such as birds, small mammals and amphibians could get trapped). For this reason, it is recommended to used mesh rather than netting, or a solid barrier such as a cloche.
● If birds are persistently eating the seeds/very young seedlings, it may be better to sew in protected seed trays and grow indoors until plants are big enough to plant out.
● If rats are causing a problem, you can deter them by moving things around often - they don't like frequent change.
● Turn compost often if you think they may be nesting there. They also won’t like wet compost heaps.
● Collect harvest promptly and don't let food rot on plants.
● Consider storing seeds, bulbs etc in rodent-proof containers.
● Allow room for their natural predators, such as foxes and badgers.
● Pull out weekly - as much as you can. Try not to break the root as this can develop into a new plant.
● Once an area is clear, you can mulch heavily to reduce the chance of any new plants reaching sunlight (e.g. place cardboard layer on top of cleared area, and add a layer of bark/soil on top).
● Don’t put roots directly on the compost heap. Seal in dark container with no holes where light can get in (such as an old compost bag or specific bin) until completely dead (roots no longer white). This can take a year, but once dead these roots can be composted as normal.
● Key predators of aphids (blackfly/greenfly) include hoverfly larvae (which look like small maggots) & ladybirds. You can improve hoverfly habitat by providing lots of flowering plants as a food source for the adults - see https://www.gardenersworld.com/plants/the-best-flowers-for-hoverflies/.
● Provide suitable hibernation sites for ladybirds and lacewings. They like spaces behind tree bark and in dead wood - you can replicate this with log piles, dry piles of dead leaves, piles of tree bark or pine cones.
● Companion planting - this is when you grow a plant nearby, either to repel a pest, or to attract a predator of the pest. Top plants suggested for deterring aphids include marigolds (calendula), nasturtium and garlic. Here’s an article from Gardeners World Magazine with more tips on companion planting: https://www.gardenersworld.com/plants/10-companion-plants-to-grow/
● Manual removal - plants are normally able to deal with some aphids on them. However, if your plant is really suffering, you could rub a paper towel around stems to reduce their numbers (or jet them off with a water pistol!).
Top 3 Wildlife-Friendly Gardening Tips:
1. Build a “Dead Hedge”. Not only does this give you an excellent place to store woody material that doesn't compost very quickly (such as bramble stems, woody roots, sticks, holly leaves), it provides an excellent habitat for beetles and other predatory insects - either as a safe place to hibernate, or a place for their larvae to develop. You might even create the perfect space for a hedgehog to call home! These predators are all helpful in keeping pests at bay.
2. Go chemical pesticide-free
This is one of the key ways that you can improve biodiversity and support nature’s recovery. Pesticides such as insecticides, fungicides and herbicides are one of the biggest known causes of wildlife decline. According to the 2019 State of Nature Report, 41% of species in the UK are in decline, and 15% are at risk of extinction. Many pesticides are non-selective, so will often kill more than just the target species. The damage can be far-reaching, accumulating in soils, polluting water courses, and killing wildlife further up the food-chain. You can make a huge difference by not using chemical pesticides or weedkillers.
3. Build a pond
Often quoted as one of the “best things you can do for wildlife”. Having one near your plot means that the pond’s inhabitants (frogs, newts, damselflies, dragonflies) won't have to go far to find the smaller critters such as the slugs, snails, flies and aphids on your allotment. Ponds don't have to be big (something the size of a washing up bowl or a plastic lid of a compost bin will do nicely). You can follow this guide from Avon Wildlife Trust to make a small pond: https://www.avonwildlifetrust.org.uk/actions/how-create-mini-pond.
Here are some pages that have further tips for wildlife-friendly gardening:
● Pesticide Action Network – A guide to Gardening without Pesticides. Includes many ideas how to tackle insect pests and diseases without pesticides
● Natural England – Wildlife on Allotments Lots of ideas for how to improve the habitat on your allotment and how to manage pests.
● Royal Horticultural Society – Plant for Pollinators Get your plot buzzing with this extensive list of plants perfect for pollinators.
● National Allotment Society – Wildlife and Allotments A whole host of information about how to improve your plot for wildlife.
● Avon Wildlife Trust https://www.avonwildlifetrust.org.uk/actions/how-create-mini-pond
Books recommended at the workshops included:
● ‘RHS Do Bees Need Weeds: A Gardener's Collection of Handy Hints for Greener Gardening’ by Gareth Richards and Holly Farrell
● ‘RSPB Gardening for Wildlife’ by Adrian Thomas
A “Dead Hedge” – photo copyright Wikiuser 14GTR
● ‘The Garden Jungle: or Gardening to Save the Planet’ and ‘Gardening for Bumblebees: A Practical Guide to Creating a Paradise for Pollinators’ by Dave Goulson
We would love to hear about the wildlife-friendly changes you have made to your allotment! To get in touch, you can email us at email@example.com
The workshops were delivered as part of the People for Pollinators project funded by the West of England Combined Authority.