What herbicides can I use in the vegetable garden?

Question: 

What herbicides can I use in the vegetable garden?

Answer: 

Many home gardeners choose to avoid the use of herbicides in vegetable gardens since they are growing edible crops.  Several factors limit the usefulness of herbicides in the vegetable garden. Most vegetable gardens contain a variety of plants in a small area. This restricts herbicide use because it is unlikely that the herbicide will be labeled for all plants in the garden. In certain situations, however, a gardener can use herbicides to supplement other weed control strategies.

Pre-emergent herbicides

Pre-emergent herbicides are used to prevent weed seeds from completing the germination process.  They have limited use in the vegetable garden because they will also prevent germination and growth of those vegetable crops that are direct sown in the garden such as beans, lettuce, corn, and others.  If only vegetable transplants are used, pre-emergent herbicides can help reduce annual weeds but the timing is important.  Consult the label to apply these herbicides at the appropriate time and frequency to control weeds and not impact germination of future seed-driven vegetable crops.

Post-emergent herbicides

Post-emergent herbicides are used to kill weeds that have already begun growing.  They must be carefully applied as they have a high potential to harm both weeds and crops.  Always apply herbicides when winds are calm and temperatures are cool to prevent drift and damage to desirable plants.  Protect nearby plants with barriers like buckets, tarps, or boxes to further reduce problems with drift.  Herbicides can also be applied with a sponge and wiped onto the leaves of the weed to prevent collateral damage to nearby plants.  Herbicides must be used according to label instructions on the package. Failure to follow directions may kill desirable plants or prevent other plants from being grown in the area.

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