Ask any gardener and slugs always come out enemy number one, but to understand how to prevent slugs, kill slugs or simply deter them off your prized vegetables and ornamentals, it’s important to know a little bit more about this creature.
Most land slugs live beneath the surface, protected from predators such as birds, amphibians, and gardeners, away from the sun, but where water is available.
So, unfortunately, the number of slugs you see above ground is merely the tip of the slug iceberg, and they can travel between one and 12 metres in one evening.
Over winter the adult slug lays clutches of eggs and when environmental conditions are right the eggs mature and turn white and can take between two and four weeks to hatch.
A newly hatched slug is called a neonate. The good news is that a slug’s life expectancy is anywhere between six and 12 months, although some determined and persistent ones will live for 18 months.
Like snails, slugs are hermaphrodites and therefore capable of laying eggs through self-fertilisation.
READ MARK LANE’S MOST RECENT COLUMN: ‘Raise the mower blades’: Vital winter lawn care instructions
The terrifying news is that they are capable of reproduction after a couple of months and can lay several hundred eggs in spring and autumn.
Slugs will feed when moisture is present, which is why you find a lot of them under clods of soil, among decaying debris, in cracks in the soil, and, of course, on your plants, which contain moisture in their large central vacuole cell.
Yet, while slugs like certain conditions, such as temperatures around 16 degrees Celsius, light rain or fog, acidic soils, clay soils, seedlings, and surface debris, they don’t like dry conditions, no hiding places, driving rain, sunlight, lime/sand, more established plants, and salt!
They are more active above ground at night and after supplemental irrigation.
Monitoring and checking where you see slugs is the first stage in dealing with them. Preventative measures along with monitoring are more sustainable approaches to this garden enemy.
‘Really good’: Mark Lane solution to kill weeds ‘down into the roots’ [TIP]
How to get rid of slugs: ‘They barely crawl over it’ [EXPERT]
‘Perfect’ baking powder solution to kill weeds on your path [COLUMN]
Gently cultivate soils to expose slugs. Turning over soil can also crush and bury slugs. Where possible remove piles of debris, clods of soil, old paving, bricks and check over garden ornaments, the perfect spots for adult slugs to reside.
As far as biological agents or natural enemies are concerned, I mentioned nematodes in a previous piece, which are parasitic and when mixed with water and poured over the soil, go in search of the slugs.
But aim to bring in omnivores, such as birds, starlings, and blackbirds in particular, to your garden to feast on the adults, as well as the clutches of eggs. Ground beetles and grass snakes will also feed on slugs.
Interestingly, invertebrate predators, such as daddy long legs, centipedes, and spiders will also help with the battle against slugs. Frogs, toads, and hedgehogs are also great allies, so make your garden as wildlife-friendly as possible, and garden organically to help maintain the natural balance.
When it comes to chemical controls, such as pellets, bait, and liquids I urge you not to use them in your garden.
There is now pet- and environmentally friendly slug pellets, such as barrier pellets that are organic, and while stopping slugs and snails from damaging your plants will also help improve the structure and nutrient levels of your soil. Another barrier method is wool pellets, which produce an effective textured barrier that slugs don’t like.
Seaweed slug repellent is a great fertiliser but hated by slugs due to the high salt content.
Mulch soils with it and add it around the base of plants. Similarly, pellets containing iron phosphate, which occurs naturally in nature, have been approved for use in organic gardening.
I think it’s important to remember that, while many of us think “what is the point of a slug?”, it is part of the garden’s food chain.
If you want to learn more about and observe this gastropod then how about growing some sacrificial plants, such as lettuces, around your prized plants.
They will, hopefully, go for these and not your favourite hosta (fingers crossed).
Our gardens should be alive with wildlife, and one final point, never use pellets that contain metaldehyde as they pose risks to the environment and wildlife.