Laura Jesse, of Iowa State University Extension’s Plant & Insect Diagnostic Clinic, wrote the following about garden slugs:
Slug photo by Laura Jesse of ISU Extension
There seem to be plenty of slugs in my garden, but I hope not in yours. Slugs leave small, irregular holes all over the leaves of plants. They especially seem to like my hostas but they are not picky feeders. Slugs are difficult to detect because they feed only at night. Slugs look like snails without a shell. They vary in size from less than an inch up to 2 inches in length, grayish colored, and a bit slimy to the touch. In fact as they crawl along they leave a slime trail.
Slugs need moisture to survive and are found under mulch, rocks, logs, and other damp locations. My hostas tend to be eaten because they grow in a garden that is shaded and holds the moisture longer.
Reducing slug damage is not an easy task and nothing will fix holes already there, so your first question should be – how bad is this and can I live with the damage? If you do decide to try to reduce the slug population you should combine several tactics. First, remove mulch and reduce moisture from around the base of afflicted plants as much as possible. Remove slugs you find either by using a trap such as a board on the ground that slugs will gather under or pan traps with beer as a bait. I assume cheap beer works fine and would not waste expensive beer on this. Remove dead slugs daily or it will get pretty disgusting. Finally there are commercially available slug baits available containing a molluscicide, but they are best used in the spring or fall.
The following is by Linn County Master Gardener, Claire Smith:
The critters sense that the weather outside will be—already is—frightful. I almost need traffic signals and turn lanes in my yard and driveway where the squirrels are frantically harvesting nuts from the walnut trees. Canadian geese have noisily moved in mass overhead traveling south. I’ve not had feedback from the deer, but they must have felt the hosta in my xeriscape was especially tasty as they have, again, totally decimated all of them as they prepare for winter snow cover.
You see, we live in the country and our road ditch is steep, difficult to weed whip and impossible to mow. We created an attractive xeriscape using mulch to cover grass and weeds and rock to stop an area of erosion, then added a few perennials for interest. Maintenance has been minimal. This spring we plan to xeriscape a smaller area on the other side of the lane. An article in a recent Master Gardener’s newsletter sparked my interest in perennial ornamental grasses. Linn County Master Gardener, Becki Lynch says ornamental grasses have few enemies. Deer, rabbits, squirrels, even insects seem to not be interested in them. Becki describes the grasses as “beautiful, regal, feather topped, silver sheened, golden stemmed, ten feet tall, back-lit by the sun and swaying in gentle breezes.” After established, ornamental grasses are drought resistant. You can fertilize them—or not. They do like mulch. And, ornamental grasses come in a multitude of heights, shapes and textures. Ornamental grasses sound like a plan to me. What do you think? Oh, when, oh when will seed catalogs start to arrive?
Even if we can’t work outside in Iowa’s winters, we can still enjoy gardening by listening to someone from the Master Gardener’s Speaker’s Bureau. A colorful and educational presentation on any number of gardening topics is available for your group or organization. Contact the Linn County Extension Office at 319-377-9839 for a brochure reflecting the range of speakers’ experience.