Americans use millions of pounds of chemicals each year to keep weeds out of their lawns and pests out of their gardens. And weed killers and pesticides work really well, but we pay a tremendous price for that effectiveness in terms of health and environmental problems. Of course, the manufacturers of weed and insect killers insist that their products are safe, but studies show otherwise…
Studies have linked household use of herbicides and pesticides with cancer, birth defects, and organ damage, as well as damage to muscular, nervous, and digestive systems. Children are particularly vulnerable to the harmful effects of pesticides. The American Cancer Society has reported that children whose homes and yards have been treated with pesticides are more likely to develop leukemia and non-Hodgkin lymphoma. And pets suffer too—a study by the National Cancer Institute found a link between pesticides and herbicides and dogs diagnosed with canine malignant lymphoma.
These chemicals enter the waterways where they cause genetic damage to fish and frogs, and contaminate our drinking water. Pesticides and herbicides may be responsible for the development of new diseases in birds and wildlife, and could even be the reason honeybee populations are dying off.
So, here’s the thing…natural methods of dealing with weeds and garden pests do not work as quickly or easily as chemicals do, but isn’t it worth a little extra effort to reduce your family’s exposure to these poisons and keep them out of our air and waterways? Organic gardening is sometimes described as working with nature instead of against it, which requires a shift in the way you think about your yard or garden and what grows and lives there.
Long-time gardeners understand that there is a balance in nature. Even the pests that eat our plants play an important role in our backyard ecosystems —they are food for other insects and wildlife. Green lacewings eat spider mites, leafhoppers, whiteflies, and caterpillar eggs; praying mantis eat aphids, flies, and beetles; and ladybugs feed on many types of garden pests, including aphids, chinch bugs, whiteflies, and mites. You can increase the numbers of these beneficial bugs by growing the plants and flowers that attract them, such as alyssum, clover, coriander, dill, fennel, marigolds, nasturtiums, and butterfly weed. Plant them among vegetables to control the pests that feast on your garden.
You can also buy these insects at most nurseries and garden centers, but they will still need certain plants if you want them to stick around. Check with your local Cooperative Extension Service for beneficial bugs that are native to your area and the plants that attract them. Some herbs and flowers are also natural insect repellants. Planting lavender, rosemary, or sage around your vegetable bed will repel snails, and dill, basil, and marigolds planted among tomato plants will discourage pests. Garden plants such as chives, garlic, onion, cilantro, and radishes are also natural pest repellants.
Researchers at the University of British Columbia found that insects don’t like certain essential oils, such as thyme, rosemary, mint, clove, and sage. Some of these oils kill insects, while others repel them. You may have to experiment to find the right strength, but start by mixing 10 or 12 drops of one of these essential oils with 1 quart of water in a spray bottle. Adding a teaspoon of liquid castile soap will help the spray stick to the plant’s leaves.
Or you can mix 3 tablespoons of cayenne pepper and 1 teaspoon of liquid castile soap with 1 quart of water in a spray bottle.
Spray garden plants no more than once a week, and later in the day rather than in full sun. After a rain, wait until the plants are dry before spraying. Even though these sprays are natural, they could be harmful to some plants. Test by spraying a couple of leaves on each type of plant; if there is no reaction after two or three days, it is safe to spray the whole garden.
Like pesticides, commercial weed killers pose serious threats to people, animals, and the earth. Some of the same toxic chemicals found in pesticides are also found in herbicides, and overly-aggressive use of weed killers has caused serious problems for farmers all over the world. Organic gardeners recommend controlling weeds with mulching, manual weeding, and natural sprays. Tilling disturbs weed seeds buried deep in the soil and brings them to the surface where they germinate. It also breaks down the structure of the soil and kills the beneficial insects, bacteria, and fungi that healthy plants need. It is better to leave deep soil undisturbed and use mulch to control weeds and organic fertilizers to enrich the soil.
Like any other plant, a weed seed must have sunlight in order to germinate. Mulching prevents weeds from sprouting by keeping the seeds in the dark. Organic mulches such as wood chips, leaves, straw, pine needles, dead leaves, grass clippings, and compost also add nutrients to the soil as they decompose. Spread the mulch in a layer about one inch thick and leave it on the surface of the soil. Replenish the material as it decomposes.
Mulch retains moisture, so keep it about an inch away from plant stems to avoid rot. Newspapers also make a good weed-controlling mulch, just make sure not to use any with colored inks. Some natural mulching materials can affect the pH of the soil, so it is a good idea to check with your local Cooperative Extension Service or visit the Natural Resources Conservation Service website at www. nrcs.usda.gov for more information on mulching and soil pH.
Pulling weeds the old fashioned way is not as much work as you may think, the trick is to get them when they are small and stay on top of the situation. Use a weed-pulling tool with a forked end and try to get as much of the root and runners as possible. Weeding is easier if you do it right after watering or after a good rainfall when the ground is soft. But even if you weed your garden regularly, there will be times when you need some help…
Vinegar is great for killing weeds because it draws the moisture out of the leaves. Make a weed spray by dissolving ¼ cup of salt in 1 quart of white vinegar; add 2 teaspoons of liquid castile soap, mix well, and pour into a spray bottle. The soap causes the mixture to adhere to the leaves so the vinegar can do its work. Get the weeds really wet, using the stream setting on the spray bottle, and be sure to spray only the plants you want to kill. This works best on young weeds, so you may need to reapply it to hardier weeds.
Mulching and weeding consistently will reduce weeds over time, but remember that weeds are just plants that happen to be growing where we don’t want them to be. And some weeds attract the good bugs that keep the bad bugs away, so a few weeds might not be a bad thing.