I am all for using mulches to control weeds in the vegetable garden. However, there are times when the problem weeds are easier controlled with an herbicide. There are only a few herbicide options available for home gardeners to use in a vegetable garden. The first, sethoxydim, is primarily effective against young grass seedlings that are less than 6 inches tall. It also has a long pre-harvest interval for many crops. Pre-harvest intervals are the number of days between when you use a pesticide on a particular crop and when you can safely harvest the produce. It is critical to read the label closely before treating the garden with this product.
The other herbicide option for weed control is glyphosate. Glyphosate is a broad-spectrum herbicide that cannot be used directly on fruit or vegetables. During the growing season, it can be used around the perimeter of a garden or as a spot spray in aisles and walkways during the growing season. Take care to avoid spraying on windy days, and you may want to use a piece of cardboard as a shield to prevent overspray or drift onto desired plants. Applying the herbicide using a wick applicator is another option to keep the herbicide from impacting desired garden plants. Glyphosate can also be used to treat persistent perennial weeds either before or after the garden is planted. If spraying before planting, allow a few weeks for the herbicide to fully work on the weeds and dissipate.
There are few good options for organic herbicides that are also safe for the soil. Do-it-yourself mixes containing salt and other household chemicals are popular on the internet, but these products are not labeled for use in edible gardens, and table salt can harm your soil with regular use. The best option for an organic herbicide is horticultural vinegar, which is a 20% solution of vinegar. This product is broad-spectrum, meaning it will damage any plant it touches, including desired crops. It is also a “burn down” type herbicide. This means that the product will burn back the top growth of the weeds, but it will not kill the roots. It may be effective against annual weed seedlings, but it will provide only a very temporary solution for large weeds or perennial weeds.
