How To Get Rid of Garden Slugs
Is your Alberta garden plagued with slugs? Are unsightly holes disheartening your hostas?
In this blog, we will talk about the life cycle of slugs, where slugs typically live, how slugs damage plants and share some simple and effective ways to get rid of slugs in your garden.
What are Slugs?
Slugs can be thought of as shell-less snails. Most slugs in Alberta are grey or brown or a mottling of these two colours. Slugs are legless soft-bodied animals that have one foot called a monopod (‘mono’ meaning ‘one’ and ‘pod’ meaning ‘foot’).
Slugs range from .75 cm (¼”) to 5 cm (2”) in length. Fortunately for us in Alberta, we see slugs that are on the smaller end of this scale. Rarely do we see slugs that are larger than 2.5 cm (1”) long.
Slugs have 2 pairs of feelers – a large set and a smaller set.
Their large feelers are located on the top of their heads and these are the ones that have eyes.
The smaller, lower pair is harder for us to see and that set is for smelling.
Slugs are covered with a slimy coating that protect their soft bodies from a variety of threats like predation and desiccating. Keeping moist is a key factor in slug survival and habitat choice. Slugs also use this slime to lubricate their locomotion as they propel themselves through their environment. Slime leaves shiny telltale trails as to where they’ve been and what plants they have been visiting.
Signs that you have slugs in your garden include irregular holes in leaves, shiny trails, and excrement on leaves.
The Lifecycle of a Slug
Due to their necessity in keeping their outer skin moist, slugs live in damp, cool, and shady areas. Cool and shady habitats decrease metabolic needs and lower the evaporation rate of moisture – that’s what makes any shade garden is prime real estate for these creatures.
Slugs live throughout the growing season – there are many variations in how they emerge and grow through the season from spring to fall. Slugs generally don’t have one flush of hatching like Scarlet Lily Beetles, for example, but eggs hatch and populations increase as the season wears on. How quickly the population increases depends on how wet the weather is. Slug populations grow at a faster rate in rainy years.
Many strains of slugs lay their eggs in autumn once the young slugs have matured to adults. Some lay eggs in clusters and others lay them singly. Slug eggs range in colour from translucent to white to golden. Slugs deposit their in the soil or underneath things like leaves or mulch, rotted plant material, pots, logs, old boards, stones, and any material or accents like birdbaths or benches in a garden. Some slug species hatch in the autumn with the baby slugs overwintering underground during the cold season. And other slug species lay eggs tough enough to survive our Alberta winters. Slug eggs can stay in limbo for years until the conditions are right for them to hatch.
Baby slugs are quite vulnerable to predators like birds, snakes, beetles, spiders, amphibians, and other slugs.