Know Your Molluscs
While the black slug may look intimidatingly large, it does relatively little damage to growing plants, other than in early spring. Smaller slugs such as the field slug (Deroceras reticulatum), the Budapest slug (Tandonia budapestensis) and the garden slug (Arion hortensis) are far greater pests. Damaging snails include the garden snail (Cornu aspersum), the strawberry snail (Trochulus striolatus) and the white and brown-lipped snails (Cepaea hortensis and C. nemoralis). See habitas.org.uk/molluscireland
Keep A Tidyish Garden
Slugs love cool, dark places where they can hide from bright sunlight, and are attracted by decaying vegetation. So keep beds as neat and weed-free as possible, and make a habit of regularly checking the bases of plant pots and trays. Hoeing in spring will also bring slug eggs to the surface where they’ll be eaten by birds and insects.
Encourage Natural Predators
Incorporating hedges, garden ponds, trees, nest boxes and bird-feeders into a garden will attract birds, hedgehogs, frogs, marsh flies and ground beetles, all of which will help to keep slug/snail populations down.
Grow Plants ‘Hard’
Seasoned gardeners know that tender seedlings/transplants raised indoors in a polytunnel or glasshouse are caviar to slugs and snails, so make sure to harden them off well before planting them out. Lush plants that have been overfed are also a target, while certain plants (hostas, delphiniums, dahlias) are simply irresistible.
Grow Slug-Resistant Plants
Try astrantias, crocosmias, euphorbias, hellebores, Japanese anemones, perennial geraniums.
Use shallow containers almost sunk into the soil and filled with milk or beer (leave a 1-inch lip to protect ground beetles from drowning).
Collect Them By Hand
This is by far the most effective method of control, but it comes with a big yuck factor (a few stiff drinks helps). Best done at night, by torchlight, wearing gloves. When it comes to slugs, mollusc expert Prof William Symondson suggests impaling them on a sharp hat-pin or similar needle-like item bound tightly to a stick with string, then dunking the bodies in boiling water.
Poisonous pellets kill slugs and snails and can be based on methiocarb, metaldehyde or iron phosphate – if at all possible try to use the latter, which is organically friendly but can be surprisingly difficult to get your hands on. Always scatter pellets rather than put them in little piles.
The nematode control, “Nemaslug”, “Super nemos organic insecticide” or Phasmarhabditis hermaphrodita (available from most good garden centres) offers good control against slugs. However, it’s only slightly effective against snails, whose tough shells offer protection, while, given its relative cost, it’s best suited to smaller gardens.
Use Physical Barriers
Copper strips, soot, crushed eggshells, coffee grinds, sharp grit and plastic bottle cloches all offer some protection, although wet weather reduces their efficacy. Some gardeners swear by pellets made from sheep wool, which expand to form a barbed barrier (see sluggone.com).
For more growing tips and resources visit www.giy.ie