Top Tip: As well as attracting natural predators, removing the tips of broad bean plants after the plants have grown several trusses of flowers, is also a good way to limit the damage caused by blackfly which prefer the tender young growth found at the tips.
Several bird species, frogs, toads, some spiders, slow worms and various species of ground beetle all eat slugs, so turning your garden into a wildlife haven will mean that there are plenty of natural predators, happy to provide their pest control services for free. I know several gardeners who keep ducks for their slug eating services, their view of the problem being not too many slugs, but rather a deficiency of ducks.
3. Look After Plant Health
Organic gardening works on a “prevention is better than cure” basis. Healthy plants will be much less susceptible to pests and diseases so taking care of soil health and making sure plants have the right conditions for healthy growth is key. Feed your soil an organic diet, adding plenty of organic matter to promote long-term health and fertility and to keep those lovely worms and microorganisms happy! Find out about the requirements of different plants – what type of soil do they need, do they need full sun or some shade, how much water do they like? Giving your plants the TLC they need will make them stronger, more robust and more resilient to pests.
4. Use Barriers to Protect Plants
Young plants with their tender new growth are particularly susceptible to pests. For slugs and snails, a copper barrier can be very effective. It gives any approaching molluscs a harmless electric shock so they don’t like to climb over it. You can buy copper rings to place around plants and also copper tape to stick around plant pots and growing containers. It’s also possible to fashion your own barrier out of old pieces of copper piping, as long as it completely encircles the plants you want to protect. If you leave a gap, slugs and snails will soon find the “doorway” you have left them.
Old plastic bottles with the bottoms cut off and lids removed are another effective barrier, useful for individual plants, such as beans, cucumber and squash. Old 2 litre bottles are fine for beans, for larger plants the 5-litre water bottles work well.
Birds love many of the soft fruits, tree fruits and brassicas that gardeners grow. Netting around a simple wooden frame works well to protect brassicas, strawberries and other soft fruit crops. Small and medium trees like cherries can be protected with netting too. Make sure that the netting is fine enough that birds won’t get trapped in it. If you use an insect-proof netting for brassicas, it will also protect the crop from cabbage white butterflies who lay their eggs on
members of the brassica family. Carrots can be protected from carrot-root fly by using a horticultural fleece covering the crop or with a barrier of fine mesh or polyethene placed around the crop. Because carrot flies are low flying insects, the barrier only needs to be around 60cm high.
5. Experiment with Deterrents
Talk to several gardeners and they will probably all have a different suggestion for what material to use as a slug and snail deterrent, ranging from coffee grounds and eggshells to sheep’s wool and human hair. The idea with all these deterrents is that slugs and snails don’t like to cross over them in order to get to your precious plants. Experiment with what you have to hand. If you have a wood stove, wood ash sprinkled around plants can be effective, though as with many materials, you do have to keep applying it regularly if it rains. Some gardeners swear by using a mulch of coffee grounds, so that’s a good one to try if you’re a coffee drinker or if you live near a coffee shop and can procure a supply of used grounds.
For birds, try making a home-made deterrent by hanging up an old CD or DVD on some string. The idea is that shiny metal objects reflect the sunlight and keep feathered scavengers away. Birds are savvy though and they’ll soon work out that something isn’t dangerous. Try switching it up using different shaped objects such as scrunched up bits of tinfoil coiled into a spring shape or strips of white cloth. It’s also a good idea to hang these up at the last minute, just before the fruit is ripe for example. Put them up too early and their effectiveness will wear off before they’re needed.
6. Adopt a Mixed Planting Approach
Mix it up when it comes to planting and avoid ‘mini monocrops’. If you grow a whole bed of nothing but lettuces and slugs and snails come calling, without good protection the whole crop could be lost. You can grow alternate rows of different crops or use a ‘polyculture’ vegetable growing method where you grow several vegetables together in the same bed. With this method, if you lose some crops, you’ll still have plenty of others and having the plants all mixed up together makes it more difficult for the pests to find their favourite food. To adopt this method, you have let go of the idea of tidy rows or large blocks of a single vegetable in favour of an eclectic mix of plants. It’s a very effective approach that mirrors the type of plant diversity found in natural ecosystems.
7. Use Companion Planting
Companion planting is another great way to help with natural pest control in the garden. Growing herbs and flowers among your vegetables can help to both attract natural predators and also deter pests with their scent. Try growing chives and spring onions alongside carrots to confuse carrot root fly who sniff out carrot crops with their keen sense of smell. Mint is a great herb to have in the veg patch for deterring flea beetles that eat small holes in brassica and salad leaves. Basil is a classic companion plant for tomatoes, its pungent smelling leaves helping to deter aphids (and of course basil and tomatoes go great together in the kitchen too!).
8. Collect and Remove By Hand
Picking off pests by hand and removing them away from your plants can help limit any damage caused. If you have a bad problem with slugs and snails, I recommend going out at night with a head torch when gastropod grazing is in full swing and simply picking them off into a bucket. You can take them some distance away and release them. It’s possible a few will find their way back, but I find collecting and removing, combined with a barrier method works well, especially for smaller gardens and containers.
My children adore snails and have recently been creating a snail and slug habitat at the bottom of the garden. They collect up any snails they find around the veg beds and put them in a shady, damp area where they feed them with chard, spinach and salad leaves that have been rejected from the kitchen. The snails are free to come and go, so time will tell whether this ‘collect and relocate’ method will be effective. In the meantime, the children are thoroughly entertained and learning about snails, a valuable bonus.
9. Use Transplants Instead of Direct Sowing
If you’re having problems with direct sowing crops because slugs and snails are hoovering up the emerging seedlings, try growing plants in modules or pots and planting them out when they have reached a decent size. If sown indoors, make sure you harden-off the young plants by putting them outside during the day and bringing them back in at night for a few days before planting them out. Slugs and snails love tasty young plants so use one of the barrier or deterrent methods discussed above for added protection.
10. Aim for a Balanced Ecosystem
It might sound counterintuitive but don’t try to eliminate garden pests. Instead, focus on creating a diverse garden ecosystem where natural predators keep those pesky critters in check. Plant lots of perennials to support garden wildlife and don’t be too tidy. Beneficial insects often overwinter in standing dead stems, so don’t clear these away from the garden in the autumn.
Slugs and snails get a lot of bad press. They’re the bane of many a gardener’s life. But these gastropods are also fascinating creatures that play an ecologically important role, recycling organic matter and helping to create a healthy soil. The organic approach is not about eradicating garden pests, but about creating a garden ecosystem that is balanced, biodiverse, and full of natural predators. It’s important to adjust our expectations and accept that we’re going to lose a few plants to the creatures we share our gardens with. Organically grown produce may have a few holes in it, but it will still taste sublime!
I hope this article has given you plenty of ideas for different methods to try in your garden. Using a combination of methods is often the most effective approach, so do experiment and find out what works best in your particular garden setting. Talk to neighbouring gardeners to find out their tips and spread the word about the dangers of pesticides and wildlife-friendly alternatives.