Release the slugs! Admittedly, a command from Zeus to punish humanity with slugs carries less caché than letting loose the Kraken. But to gardeners in the Pacific Northwest and their tender young plants slugs can present a terrifying challenge. More than a few gardeners have awakened one morning to find their newly emerging hostas chewed to skeletal remains, or their neat rows of spring lettuce reduced to, well, neat rows of dirt.
Some comparative studies about garden pests have demonstrated that slugs pose a greater threat to northwest gardens than any pest in other regions of the country. Of course, I doubt whether northeast gardeners really care about our plight with slugs while battling Japanese beetles on their roses. But these studies do, at least, reaffirm local gardeners' fears for their tender plants. And if you have environmental concerns about the effects of chemical pest control, you may also fear that your options for combating slugs are limited to more tried than true methods, like beer traps.
Despite their reputation, slugs can be controlled and even eliminated from your garden. In fact, organic gardeners have a large arsenal for defending against the onslaught of slugs this spring, ranging from non-toxic baits to "slug wise" landscaping.
NON-TOXIC SLUG BAITS
Traditional metaldehyde slug baits have a horrible record of poisoning pets and wildlife, and should be avoided at all costs. When pelletized slug bait can look like kibble to a dog, or like bird seed to birds. Baits are often flavored with molasses or bran, making them even more attractive to your pets. And very little snail bait is required to cause poisoning, less than a teaspoon per 10 pounds of body weight.
Iron phosphate bait -- considered safe for food use by the EPA -- offers an effective, non-toxic alternative to traditional metaldehyde slug bait. At first you might not realize that the slug bait is working because you don't find dead slugs laying around in your yard. But rest assured that the slugs have taken the bait, stopped eating your plants, and crept underground to die. One local nurseryman told me recently that he has completely eliminated slugs from his garden after just two years of treatment with iron phosphate bait.
Despite the non-toxic nature of iron phosphate, you still need to be careful. It is possible to overdose on iron. To avoid any risk, it is recommended that you not leave piles of slug bait in your garden and that you sprinkle it lightly on the ground, dispersing it evenly through your garden.
TIPS FOR CHEMICAL-FREE GARDENING
If you are like me, you might find the idea of adding any chemicals to your garden a little disturbing, and wish to avoid chemicals of any kind. You still have a variety of methods for controlling slugs.
Copper tape is one traditional method of slug control, although the method gets mixed reviews. Copper tape carries a small electrical charge that repels slugs and snails. Apparently, the electrical charge makes the slugs uncomfortable, and they won't cross over the tape. If your copper tape barrier is going to work properly, make sure that you don't have any breaks in the barrier and clean the copper surface periodically.
Other barriers that may discourage slugs from approaching tasty leaves include wood ashes, diatomaceous earth, and pine needles. Like copper, slugs don't like crawling over these materials and will avoid them in your garden. However, all of these materials have their drawbacks. Wood ashes are alkaline, and can lower the pH of your soil. Pine needles are acidic and may raise the pH of your soil. Diatomaceous earth has to be applied frequently, and, when inhaled, can irritate your lungs in the same way that it cuts up a slug's skin.
My personal preference for slug control is to use "slug-wise" landscaping. Slug-wise landscaping simply means that you plan your landscape to discourage the presence of slugs and snails in your garden. With a little homework you can find out what plants slugs are most attracted to, such as hostas and red clover, and avoid using those plants in your garden, or at least isolate them away from your vegetable garden and tend them carefully.
Plant flowering shrubs that attract birds. A garden with a healthy balance of plants, insects, and birds creates a more natural balance in your garden that will discourage an infestation of any kind of pest. Flowering shrubs like Flowering Currant, Mahonia, Viburnum, and Callicarpa add beauty to your landscape and attract birds, which in turn will eat any slug unfortunate enough to be caught foraging in your yard.
Regardless of your chosen method of slug control, starting before the slugs get out of hand is the best way to prevent an infestation. When it comes to garden pests, "an ounce of prevention is worth a pound of cure."
With a little diligence you should be able control the slug and snail population in your garden, if not eliminate them. Whether you are using non-toxic baits or old-fashioned barriers, slugs and snails should not cause too great a problem in your yard, especially if your landscape includes fewer slug-friendly plants and lots of birds. Considering all these tools available to you to fend off slugs, you might think that the God of Abraham had it right when he sent locusts to plague the Egyptians. Just a thought.
Photo Credit: By Tobyotter