I have been very busy this weekend (sunny at last!) with the garden tour. Here is an interesting and useful post by our friend and Master Gardener colleague, HerbDoc:
The cold and wet May and June weather has spawned an unwelcome and destructive visitor in the garden. Slugs have been feeding on many of the ornamentals, leaving holes and rasped areas on what were perfect specimens.
Slugs are classified as gastropods, more closely related to clams and mussels than insects, so most of the pest control methods on the market simply don’t work. They aren’t often seen in the day because they’re susceptible to drying out so they seek shelter under pots, boards, large chunk mulch, grass, straw, etc. In my yard, I found a bunch camping out under three bags of mulch! They sneak out after dark to feast on vegetables and ornamentals.
There are molluscicides which are pesticides that cause intense irritation and death to slugs and snails on contact. Metaldehyde (sold as Bug-Geta) is effective for ornamentals but cannot be used near vegetable crops and is deadly for dogs or children if ingested. Iron phosphate (sold as Sluggo, Escar-Go! etc.) is as effective as metaldehyde but can be used in vegetable gardens and doesn’t pose any hazards to dogs and children.
My favorite way to get rid of slugs is to bury shallow tuna cans up to their rims and fill them with beer. Slugs are attracted to fermenting materials so they climb in, get drunk and drown. They die happy, and I’m delighted to be rid of them! A container will last several days as long as some liquid is present. Just keep discarding the dead bodies and adding new beer until there is no further evidence of them. I also check under my large pots everyday and destroy any slugs lurking beneath.
Keep an eye out for these creatures in your garden! They lay eggs in soil crevices, and since they can eat forty times their weight in a night, can do a lot of damage in a very short time.