They eat their way through the garden under the cover of night, leaving a slimy trail to show where they’ve been.
A nocturnal menace to the garden in the warm months, snails and slugs have a huge appetite for many types of plants.
They love vegies, especially lettuce, but are happy to sample other delicacies from the spring garden smorgasbord.
Left unchecked they’ll attack flowers, with annuals like pansies and violas a favourite feast.
These pests like moist soil and are most active during cool weather and humid periods, so they’re especially busy in spring and early summer.
At night, snails and slugs climb onto plants to eat foliage, hiding in leaf debris or sheltering under shrubs during the day.
Signs of invasion
Before using pest control in the garden it’s essential to correctly identify the problem and use the appropriate technique or product.
If you know what to look for it’s easy to spot when gastropods are helping themselves to your plants.
Healthy seedlings can disappear overnight, plus foliage and flowers show ragged or chewed-looking holes with the lower leaves of plants usually consumed first.
Snails and slugs also leave a trail, so look for shiny streaks on foliage and silver-grey slime trails appearing on the plant, soil or pots.
The best way to catch them in the act is to search for them by torchlight, before sunrise or after dark.
Methods of control
The only sure-fire way to keep your garden free of snails and slugs is to destroy them. There are several ways to do this, or you can use natural deterrents to keep them away from your plants by making the garden less hospitable.
Scatter pellets or apply a snail gel around plants by hand, choosing an animal-friendly product to protect pets, native birds and lizards.
Set traps baited with fresh lettuce, citrus rind or stale beer, check them daily and squash the pests or drop them into a jar of salty water.
Use copper tape as a collar for young plants and pots, or as bed edging. Copper makes an effective barrier, as it gives snails and slugs a slight electric shock. This tape is about 30mm wide.
Search and destroy snails and slugs by hand-picking them out of the garden and killing them. If you can’t bear to squash or drown them, mix a solution of equal parts vinegar and water and pour it into a spray bottle for a homemade and eco-friendly pesticide. Spray the solution directly onto both snails and slugs to kill them, but be careful where you use it as vinegar is a herbicide and will also poison your plants.
Position timber boards on the soil near vulnerable plants and the pests will migrate to the underside where they can be easily removed. Clear away decaying vegetation and debris like rocks and leaf litter to eliminate daytime hiding places. Mulch also makes a good home for snails and slugs, so keep it less than 80mm thick.
TIP Don’t spread mulch until plants are well established and daytime temperatures are reaching 21°C.
Lay barriers around plants, especially lettuces, to stop snails and slugs in their tracks. These soft-bodied pests will turn away from a sharp or scratchy barrier rather then crawl across it to get to the salad bar. Surround plants with strips of coarse grit abrasive paper or broken eggshells. Coir also works, as the tiny fibres stick to snails and slugs, making it hard for them to move.
Make a beer bait
Slugs and snails are attracted to the sweet, yeasty combination of sugar and beer, making it the ideal bait.
Sink a shallow bowl or tub in the ground with the rim at soil level.
Stir a pinch of sugar into 150ml of stale beer then pour the mixture into the bowl to a depth of 30mm.
The pests will crawl into the beer for a drink and drown.
Empty and refill the baits every two days.