Weeds are a mixed blessing in any garden. Most gardeners can rattle off the bad points of weeds without hesitation. Weeds compete with cultivated plants for precious supplies of light, nutrients, and water; they may harbor pests and diseases that readily spread to food crops and ornamentals; some are poisonous or allergenic; many seem nearly impossible to eradicate; and finally, almost everyone objects to spending time and energy getting rid of them.
Considering all that, chemical herbicides may seem like a remedy for gardeners. With a quick, easy spray, weed problems are eliminated. But there are hidden costs to using herbicides. They are toxic chemicals that may be health hazards to the people who apply them or to those who are exposed to them when they walk, sit, or play on the lawn. They may persist in the environment and may have detrimental effects on beneficial soil organisms if they are applied to the soil or are washed in by rain.
Given the potential dangers of herbicides, the time and physical effort you devote to weeding could be one of the wisest investments you make in your garden. Organic gardeners combine a few basic strategies to create an effective weed control program without using synthetic herbicides.
Precise identification: Planning a strategy to control weeds is most effective if you know exactly what type of weed you’re fighting. Control methods vary for annual, biennial, or perennial weeds.
Cultural controls: You can adjust your gardening practices to help avoid many weed problems. Using mulches to smother out weeds is one of the easiest and most effective techniques for weed control. It also provides the benefits of increasing soil fertility and reducing water loss from the soil. Using cover crops and green manures are other cultural practices that help with weed control.
Physical controls: Old-fashioned hoeing and hand pulling are two skills every organic gardener should refine so they become a pleasant pastime rather than a pain in the back. Power tools can also be used for weed control.
Chemical controls: Vinegar, salt, and one relatively new soap-based herbicide are the only organically acceptable chemical weed control methods. They are a last resort of limited use in your yard and garden.
Fortunately, weeds can be as helpful as they are troublesome. Sorrel may be a weed, but it’s also a tasty and nutritious addition to your salad. Some weeds are good medicine, many are lovely ornamentals when properly confined, most contribute to soil and crop health. You can use weeds to help learn about the soil conditions in your garden and to attract insects that will prey on pests that are damaging your food crops.
As you learn to use chemical-free techniques for weed control, the benefits of having some weeds in your gardens may become more apparent. Eventually, depending upon the techniques and habits you develop, you could even come to regard them as allies that help promote good soil and plant health.