The late horticulturalist J. C. Raulston said "a weed is a plant dealing with an unhappy person." This holds true whether you're a gardener who uses broad-spectrum chemicals for weed control or an organic gardener looking for more natural solutions. Luckily for the organic crowd, there are a number of effective methods that can keep the garden tidy without introducing unwelcome substances.
Hand Removal and Cultivation
Perhaps the simplest, yet most time-consuming, method of weed management is hand removal. It allows the gardener to remove weeds very close to crop plantings without damaging those plantings. If you're working with a large plot, there are mechanical cultivators that can perform this task, but for home gardens, a sturdy hoe is usually all you need.
Mulching is another tried and true method of organic weed control. It works by blocking the light to the soil and preventing the germination of weed seeds. A large number of options exist when it comes to choosing your mulch material, from newspaper and other forms of sheeting, to grass clippings and wood chips. If using newspaper, use several stacked sheets for adequate light blockage. The added benefit of using organic materials like compost or wood chips is that they return nutrients to the ground as they break down.
Flame weeding is another organic solution to weed control. A propane-fueled weeder is used to heat the foliage of weeds until the cells rupture, disabling the system that feeds the plant roots. Some crop plantings tolerate the presence of this heat source better than others, so do a little research before using this method. Use a hood on your weeder to block the heat from reaching neighboring plants.
A limited number of herbicides are acceptable for use in an organic garden, including acetic acid and corn gluten. Acetic acid is vinegar, but should be used in higher concentrations than that of household vinegar (5 percent) for effective weed control. The Pennsylvania State University College of Agriculture found that using a 20 percent acetic acid solution provided 90 percent weed control in 24 hours. With three subsequent applications over nine weeks, this level of control was maintained.
Corn gluten is a pre-emergent substance applied to the soil to disrupt weed germination.