Mollusks (Garden Snails & Slugs)
imported garden snail has been in our area now for some time and has become a problem in certain Seattle neighborhoods. The
brown garden snail (helix aspera) was introduced from Europe by people who consider it to be a culinary delicacy. They arrived
here via California.
The slug is a native pest and very well adapted.
and snail damage herbaceous plants and other low growing vegetation. They chew irregular holes with smooth edges. Silvery
slime trails are left behind. Hostas are a snail favorite. Slugs and snails are active during mild damp periods, throughout
the night and early morning. Slugs hide in the soil during cold and hot periods. Snails seal themselves off in their shells
to conserve moisture during warm days.
Biological Controls- Ground beetles, pathogens, snakes, birds, ducks, and chickens
can help control your mollusks population. If you are able to make them welcome in your landscape, foul will reward you with
a virtually slug free garden.
Hand picking- at evening when the mollusks are active, inspect all hiding places and damp areas.
When found drop in soapy water, alcohol, or throw container, with mollusks, in the freezer for a quick kill. The dead bodies
can be thrown in the compost.
Beer Traps- sink a small container such as a butter or chip dip
tub into the soil. Add beer. The mollusks are attracted to the yeast and will fall in and drown.
Boards- Put out wooden board squares about one foot square and raised off the ground by one inch runners. Check
under the boards in the evening. Crush and depose the pests you find in the compost.
Copper flashing or screen can be placed easily around raised beds to keep slugs and snails away. The slimy mollusk will get
a shock when crossing copper. You must also use controls inside the copper barrier- for the mollusks trapped within. Diatomaceous
earth, wood ashes, and sand are also effective barriers.
Pesticides- Traditional slug baits are
very poisonous and may poison pets or people. New organic based slug barriers & baits are available. Sluggo® is
made of iron phosphate and breaks down into fertilizer for your plants. There are citrus based baits are also available.
These products are available at home and garden centers.
General Management Tips:Avoid over watering. Irrigate in the morning so that it is dry by evening.
Reduce and eliminate daytime hiding places such as boards, stones, debris, wild areas, low growing branches, dense ground
covers such as ivy.