Protect your plants from slugs without chemical nasties
For me a garden is nothing without the wildlife that it helps sustain.
I love pretty-much every creature that makes it home in my garden: from the family of badgers who use their huge paws to helpfully rearrange rockery stones to get to worms; the delightfully disruptive squirrels who insist on checking out every bulb I plant; through to the playful foxes that steal my shoes if I forget to take them in at night
I even love the 1,000 strong flock of starlings that fledge in our trees every May only allowing us four hours sleep a night with their incessant cries for food. (read my blog on how to protect plants, lawns and bulbs while encouraging wildlife).
The one garden visitor I can do without is the slug. My shady woodland garden, with multiple dry-stone walls, is a paradise for the shell-less, terrestrial, gastropod molluscks commonly known as slugs.
I use as few chemicals in my garden as possible and that includes the metaldehyde that makes up the main ingredient of most slug repellents. Metaldehyde is poisonous for most garden wildlife, including animals such as hedgehogs who eat the slugs that have consumed this slug bait. In addition it is dangerously toxic to dogs and it's just something I don't want to risk using in the garden.
So how can you grow the hostas, delphiniums, dahlias and tulips, among many other types of plant, that make up a slug's preferred diet?
Organic slug control
We have had great success with organic slug control containing ferric phosphate (iron phosphate). As ever, there are many different opinions as to the effectiveness of slug bait based on ferric phosphate but there is unilateral agreement that it is not harmful to humans, pets or wildlife. Trials led by the RHS are due to be published soon assessing the effectiveness of all different types of slug control (including ferric phosphate) – I've put the link at the bottom of the article.
Valentine's Day Massacre
Start early! I can't remember which hosta expert gave me this advice at one of the RHS shows but it has stood us in good stead. Every Valentine's day, Sarah and I head out into the garden at night after our own celebrations and start the massacre by spreading ferric phosphate pellets around. This is especially important after a mild winter as there hasn't been enough cold to kill off the dormant slug population; this year we were already seeing slug presence around the garden in early February.
This is the ultimate “stitch in time saves nine” approach: each slug (they are hermaphrodites) - can lay up to 300 eggs a year with each baby slug capable of producing their own eggs within 3 months of hatching. You can imagine the nearly exponential growth if you let that first slug lay eggs...