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.
Asian lady beetle - a good bug (photo/Cindy Hadish)
Their names are similar and they’re from the same region of the world, so I can see why some people are still confused about Asian lady beetles and Japanese beetles. But when it comes down to it, there’s really no comparison. The bug pictured here – the reddish/orange lady beetle, is a beneficial insect. It feeds on aphids and other plant pests and doesn’t destroy anything, though I realize some people resent their intrusion in homes in the fall. On the other hand, the copper-colored Japanese beetle, a recent foreign invader in Iowa, is known to devour at least 300 plants, including hollyhocks, roses, raspberries, linden trees and grapes. If you see your leaves turning to lace, the likely culprit is the Japanese beetle. Japanese beetles have no known predators here, other than me. So feel free to get rid of as many as you can. As mentioned previously, the most environmentally friendly method is to knock them into a bucket of soapy water when they’re sluggish – early evening seems to be the best time. If you have other suggestions – maybe from our East Coast readers and others who have learned to cope with Japanese beetles – please add your comments below.
Japanese beetles - not a good bug, or just plain evil? (photo/Cindy Hadish)
The following is by Linn County Master Gardener, Claire Smith:
The seeder wagon is in place. The lawn mower towed it out of the shed down to the water way and then with two planks and my favorite son’s strong back we pushed and pulled it to the other side of the ditch. With the addition of an old wire garden gate staked behind a sapling, a hand pump from my parent’s former home and a rock lined pseudo fire pit filled with Petunias that were on the end-of-season sale, the area reflects the peaceful primitive atmosphere I was striving for. This is the area I mentioned in an earlier blog that became inaccessible to mow due to last year’s flood. Hosta, native grasses and prairie perennials will grace the space next year. We continued our zeroscaping to include a part of the road ditch that I learned is also impossible to mow after the mower and I suffered a close encounter with the culvert. Now that waterway is filled with large rocks and what was a sloping grassy space is mulched.
Hosta will ring the two Black Walnut trees in the roadway ditch. Hosta is a plant of choice there because I have some that need transplanting and they are not sensitive to Juglone, a chemical secretion from Black Walnut Trees.
Discovered in the 1880s, Juglone is produced in the fruit, leaves, branches and root system of several trees with Black Walnuts exhibiting the highest concentration. The greatest intensity in the soil exists within the tree’s drip line, on an average 50 ft. radius from the trunk of a mature tree. Plants susceptible to Juglone display yellowing leaves, wilting and eventual death. Plants sensitive to Juglone include Peonies, Hydrangea, Asian Lilies, and Lilacs. There are multiple choices that will withstand close proximity to Walnut trees such as most grasses, Phlox, Sedum, Daylilies, Iris and Hosta.
Now my challenge is to determine plants that are not only resistant to Juglone, but also to the deer population in this neighborhood. Unfortunately, Hosta is one of the critters’ favorite choices. They have already decimated the Hosta and Bee Balm in the ditch on the other side of the lane. A great winter pastime will be comparison shopping perennials and grasses that are both deer and Juglone resistant as well as low maintenance for those landscapes.
I actually enjoy mowing. And I like the challenge of creating and maintaining flower beds, but the simple clean lines of zeroscaping does appeal to me. A few plants and shrubs easily embellish the area without overstating the purpose of low maintenance.
I spotted the first Japanese beetle of the season yesterday on my raspberry bushes. I went to check one of my rose bushes and sure enough, there was another one, sucking the life out of a beautiful pink bud. Unfortunately, both got away.
The beauty of these copper-colored beetles belies the devastation they wreak. Adult Japanese beetles feed on more than 300 types of plants – turning leaves into lacy skeletons. As larva, the white c-shaped grubs feed on turf grass roots.
I’ve heard some people have luck with the Japanese beetle traps that can be found at garden centers. Others say the traps just lure more beetles into your yard. When I see just a couple of the bugs, I use the squish method, but as they become more numerous, I’ll try to control their numbers with soapy water.
Take a small bucket with water and dish detergent – any kind will probably work – and knock the beetles off the plants into the bucket. The beetles are more active at certain times of day and will fly off. Othertimes, they do a drop and roll, which is the best way to get them to fall into the bucket. Early evening seems to be the time when they are more sluggish and easier to catch that way. Obviously, if you are growing crops that the beetles are attacking, such as grapes (another favorite,) you’re going to need a different method of control. They also favor certain trees, but supposedly they don’t kill the trees as do pests like the emerald ash borer. I also wonder what they will ultimately do to the monarch butterfly population, as Japanese beetles devastate the monarch’s food source, milkweed.
Since they make my top 10 bad bugs list, the Japanese beetle and different control methods can be found in several posts on this blog. Just use the search box at the right to find more from city arborist Daniel Gibbons, master gardeners and others on this foreign invader.
Prairiewoods is starting a monthly Environmental Lunch Group open to anyone who has a passion about environmental issues or the curiosity to learn more.
Presentations will be facilitated while participants eat lunch.
A different topic will be presented each month. Lunch is served at noon. The presentation begins at 12:15, with discussion ending by 1 p.m. The first three lunches are:
Friday, Jan. 9 – The real truth about eating locally
Thursday, Feb. 12 – Green alternative household cleaners
Tuesday, March 17 – The hazards of plastic and green solutions.
Preregistration is required for a lunch count by 5 p.m. the day before the event. Fee is $8 for lunch, or bring your own lunch at no cost.
Prairiewoods is at 120 E. Boyson Rd., Hiawatha, Iowa. To contact Prairiewoods, call Mary Ellen Dunford at (319) 395-6700.
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.