Delphi Valley

How to control pesky Snail & Slugs

Slugs belong to the Gastropod class, which means "belly and foot". Moving about by a large muscular foot. They are mollusks and are related to clams, squid and octopus. These pests are very common in moist areas of the country, especially the Pacific Northwest where they can be a very persistent nuisance.

Slugs are most active at night or early mornings, during cool, wet periods. They remain mostly inactive during hot or freezing weather. During periods of inactivity they hide in crevices, under boards, rocks. They also hide under the rims of pots and in the drainage holes on the bottom of the pots. They are territorial and will return to the same area over and over unless disturbed or it becomes to dry for them.
You can tell slug damage usually by the slime trail they leave but sometimes it can be difficult and can be mistaken for other pest damage because the trail is hard to see with juvenile slugs. Damage can occur in four stages: seeds, seedlings, young plants, and mature plants and fruit. On roots and tubers look for shallow to deep, smooth sided pits. On foliage look for removal of tissue between veins, or skeletonization, usually near the central area rather than the edge of the leaf. They also attack flowers, such as pansy, taking chunks out of the petals. They can eat 30-40 times their weight every day!

Slugs have both male and female parts (hermaphrodites). They can reproduce without another mate. They start laying eggs at three months of age. The eggs are about the size of a broccoli seed, round, pearl like, and white to translucent in color. You will find them in clusters between 10 and 100 in sheltered areas but near the soil surface. They also lay them down inside a pot between the soil and the pot wall, as well as underneath the pot in the drain holes. In a lifetime (usually 1-3 years), one slug can lay 500-1000 eggs. These hatch in 2-4 weeks, but may overwinter if laid in October - November. The greatest egg production occurs after the first late summer to early fall rains. 60% of eggs are laid in the fall, 25% are laid in the spring, and the rest are laid during warm, humid weather.
To control your slug population, it has to be a year around effort with special emphasis during the fall. Prevention is definitely the key and should include cultural as well as chemical methods.

Cultural Control

Reduce habitat. Clean up debris around your plantings. Limit the number of places they hide.
Keep your plants trimmed pruned above the ground to prevent areas for them to hide.
Space plants enough to reduce humidity and moist conditions surrounding your plantings.
Keep area free of weeds to reduce refuge and habitat.
Encourage natural predators: garter snakes, birds, rats, rabbits, moles, skunks, toads and frogs. Ducks and geese are very effective in controlling slug populations.
Stomp and crush any egg masses you discover.
Go on regular slug patrol early in the morning or after dark and destroy any slugs you find.
Use slug traps (replace bait regularly) and destroy any slugs you find.
Install salt impregnated plastic strips (Garden center store), copper bands (from roofing supply company), or copper pipe (hardware supply store) around your planting area to prevent or at least reduce re-entry into the area.
Chemical Control
Products containing Metaldehyde are the most common in slug control products. It is a very selective bait when applied around plantings. The chemical acts by paralyzing the slug for about 48 hours. If conditions are moist enough, however, they can recover and continue to feed and reproduce. Baits applied after the first rains in the fall will control the slugs before they have a chance to lay eggs. Apply them to damp ground in early evening. It will, however, have to be reapplied every two to three days if rains dilute the application. Even if rain does not occur, it seems to lose it's effectiveness in baiting the slugs after about a week. These chemical baits can be found in several formations, pellets, meals, granules, and liquid.

If you have any questions about our products, or need some help I am always available by email. Please feel free to email me and I will be happy to help you with any of your concerns.