Slug control.

Our garden is plagued by slugs. I could just ignore them and eventually nature would control their numbers. The problem is that the means by which that plays out is that the slugs gorge themselves on all the plants that they love, like the emerging shoots of Dahlias and Salvias, to the point where those plants die. When the slugs have killed everything they like, they either go somewhere else or their numbers crash for want of palatable food.

I have been getting a reasonable level of control by going out at night with a torch and chopping them in half with secateurs but it’s a big investment of time and effort and is not very pleasant to do. I may have come across a better method. YouTube is awash with videos about trapping them with a kind of bread dough slurry. Beer traps undoubtedly work but beer is too good to waste on slugs and it seems it is neither the beer taste nor the alcohol that attracts them, rather some component of the yeast fermentation process.

I have been making up a mix using a sachet of dry bread yeast mixed with roughly a tablespoon each of plain flour and sugar. This I mix into 300-400 mls of water at around 27°C and leave to stand for an hour or so, stirring occasionally. I then decant the mixture into the clear plastic pots that hummus comes in, having first made three slots in their sides. I put the lids on and place them around the garden at dusk in the places where slugs do the most damage. 400 mls is enough mixture for 6 or 7 pots. By morning there are lots of dead slugs in the pot or I’ve put it in the wrong place. I try to position the traps where they will not be in direct sunlight by day because I think they would get too hot for the yeast to survive.

For the next couple of evenings I gently swirl the mix, including the dead slugs, just as it’s getting dark and perhaps move it a short distance. It appears to attract slugs from perhaps 2-3 feet away, so it takes a lot of traps or a lot of moves to clear a big area. After a couple of nights the traps seem to attract few if any more slugs. It has become ineffective or all the slugs are dead. I tip the trap out, wash the pots out and start again.

I prepare the traps by making three slots just below the rim of the pot with a soldering iron. The slots are 25-30mm long and 5mm wide. Even the very big slugs are evidently capable of getting through them. I have also used a margarine tub but it’s opaque so I have to take the lid off too see what I’ve caught, which can get messy. It’s also bright yellow so much more conspicuous in the garden. When there’s more foliage around, the clear pots will be quite discrete.

At the moment the main target of the slimy assassins are flowers of Crocus and Scilla and emerging leaves of Erythronium. Traps put amongst crocus flowers have drawn in lots of slugs and in that immediate vicinity the problem seems to be solved for at least as long as the flowers last. I’m therefore hopeful that newly emerging shoots will get enough protection to grow big enough to withstand a low level of nibbling.

If you’re squeamish, stop scrolling!