Slugs, the one thing all gardeners can agree on. The bêtes noires of borders from Brighton to Birmingham? Right? Well, no, actually…
Here in the UK we have around 30 native species of slug, of which only four are pests. Who’d have thought these slimy critters came in so much variety? Some such as the almost-pretty leopard slug don’t eat live plants at all, instead preferring to eat other slugs and decaying leaves, so their presence is actually beneficial to gardeners.
However, it’s undeniably true that the pest species more than make up for their innocent, compost-making cousins, as anyone who’s ever planted out carefully nurtured seedlings only to return the next day to a few chewed-down stumps will know. They’re maddening, saddening and utterly frustrating; so how do we sort them out?
In order to win your battle you need to get inside the mind of the enemy. Slugs like cool, moist conditions, shelter and protection from predators. So, have a tidy up. Remove any piles of debris, either plant matter or any other rubbish. A pile of old plant pots in a damp shady spot behind the shed makes a five-star slug (and snail) hotel. That big heap of prunings you’ve not got round to moving yet? To the compost heap / fire / tip!
Tidying up helps enormously, but a certain number of slugs are inevitable in any garden, however tidy you are – research has shown that the average garden contains around 20,000 of them! If that makes you want to buy a flamethrower or move to the Sahara, then read on…
The next step in the War on Slugs is chemical warfare. Personally I don’t believe in beer traps (a waste of beer – and disgusting to refill) or traditional (metaldehyde) slug pellets. Metaldehyde is a nasty chemical that leaches into groundwater and is toxic not just to slugs but also to pets, wildlife and people. Also, with the traditional slug pellets, the unfortunate mollusc dies quickly and messily on the spot, leaving your prized plants surrounded by a sticky web of mucus and decaying slug. Yum!
Enter the ‘new’ slug pellet. Approved for organic use, these look pretty similar to the traditional types but contain none of the metaldehyde. What they do contain, however is ferric phosphate (ferramol) – which makes the slug’s digestive system grind to a halt. It crawls away and dies quietly, out of sight.
It’s important to note that with any kind of slug control it’s important to start early, to prevent numbers from building up. The life cycle of slugs, obviously, closely mirrors that of plants, so I start taking anti-slug measures as soon as I sow in spring, sprinkling a few pellets around the rows after watering.
Which brings me on to my next point. There are two main methods of slug control – slug baiting and slug barriers. Pellets are bait, NOT barriers. So you only need a few – the slugs are attracted to them and will find them – there’s no need to heap them around the base of your plants. Barriers (made from everything from copper tape to coffee grounds) work by providing a surface that the slug can’t cross – more on these next week!
With any garden pesticide (organic or not), please read the label carefully, follow manufacturer’s instructions to the letter and wash hands after use.