How Can I Control Ivy Without Herbicides?

A Reader Asks The Green Guide:

What is the best way to eliminate the ground ivy that is starting to take over my lawn without using chemical weed killer?

The Green Guide Responds:

Ground ivy (a.k.a. creeping Charlie) is a tough weed that's hard to remove by hand and thrives in shaded, wet, infertile soil. If you want to avoid an arsenal of chemicals, try addressing those root causes. Pretreat your lawn in the fall or early spring with corn gluten meal, a natural, light fertilizer that fights weeds before they germinate. Mow your lawn frequently to 2.5 inches, and leave the clippings on the lawn—if you can, use a mulching mower. Water just once or twice a week early in the morning, but deeply. Aerate a few times a year, and clear thatch when half an inch thick, perhaps every year or two. In your garden, fend off weeds by "intensive planting," growing plants closer together than is commonly recommended—perhaps six inches apart. If you weed your ground ivy, make sure to remove all debris, as it can easily regrow. Ground Ivy will root and produce stems at each leaf node that touches the soil.

Besides basic good lawn practices, there are a number of organic weed controls. For spot killing, boiling water can work—just bring your teakettle, and pour onto the weed's crown from a few inches away. Vinegar with at least 5 percent acetic acid is an effective herbicide for young weeds, working in just hours; you can find more concentrated vinegar, for older weeds and quicker killing, at farm-supply stores or in vinegar formulated for canning. A study published by Pennsylvania State University's Cooperative Extension program found that acetic acid, while not as powerful as traditional pesticides like Roundup, works very well against crabgrass, broadleaf plantain, and ground ivy, though not against the deep-rooted quackgrass. Remember: Highly concentrated vinegar can be irritating, even damaging, to the skin, eyes, and lungs, so be careful of splashes when spraying. And even with a natural herbicide, use it only in spots where weeding isn't working.

If you want to be more high-tech, there are organic herbicides available. BurnOut Weed & Grass Killer RTU is basically vinegar and lemon juice (i.e. 6.5% acetic acid). In the Penn State study, it and Nature's Glory Weed and Grass Killer RTU (with 6.25% acetic acid as well), another acetic-acid herbicide, worked about as well as 20% acetic acid over five weeks and three applications, though the concentrated acid performed better as time went on. Another option is Biorganic Weed and Grass Killer which is10% acetic acid. Matran 2, like BurnOut, is USDA Organic, but unlike the others Matran 2 does not contain acetic acid; its active ingredient is 33.7% clove oil. Sites like the Biocontrol Network's, besides offering BurnOut and MATRAN, offer other herbicides that seem safer than conventional ones. Many of them use a combination of plant oils; others are more technical. It's worth browsing, looking at MSDS (Material Safety Data Sheets) information, and asking questions to find out if they're right for your lawn or garden.

You can pretreat your lawn in the fall and early spring with corn gluten meal, spread in a push spreader. Besides providing a small amount of fertilizer to your lawn, the gluten prevents roots from forming during weed germination—that's why you need to apply it early, though reapplications can help stave off late-sprouting weeds. It works against, among others, crabgrass, curly dock, dandelions, lamb's quarters, and pigweed. Thatch is caused by too much root growth at the surface of the lawn and can be controlled by aerating during the autumn and covering with compost until spring.

More generally speaking, the more carefully you can identify the conditions specific to your lawn and garden and to your region, the better off you'll be. That's the philosophy behind integrated pest management. If you plant turf specific to your climate, identify pests and weeds and choose solutions appropriate to each, and are careful always to fit your solutions to the problems and possibilities at hand, you will have a healthy lawn and garden with a minimum of waste. In your garden, as in nature, everything affects everything else, making tailored solutions necessary. Your USDA extension office should have information on your local conditions.