Herbicides for Vegetable Gardens

• Careful herbicide use is a reliable weed control method but can be harmful to crops if incorrectly applied. It is difficult to rely on herbicides alone. There is not one herbicide appropriate for all vegetable crops, although general application of all-around herbicide containing glyphosate kills all weeds and plants and should only be applied before seeds or plants are placed in a bed. Many commercial herbicides containing either trifluralin or sethoxydim are sold in small, convenient bottles appropriate for the home vegetable gardens. Herbicides may be available as concentrates that need dilution, granules or powders to mix with water. Applying too much herbicide can harm plants, while using too little is ineffective.
  
  

Trifluralin Herbicide

• Trifluralin-based herbicides are registered for use on many vegetable crops, including broccoli, beans, peas, tomatoes and potatoes. It provides control of Brussels sprouts, carrots, eggplant, okra and kale, among others. This chemical is used on germinating weed seedlings but needs application before desired crops are present. It is available in both liquid and granular form and is effective for 12 to 16 weeks after application.
  
  

Sethoxydim Herbicides

• Use sethoxydim-based herbicide for grass control when grass is 4 inches or shorter. Sethoxydim is a liquid herbicide and is used on gardens containing cauliflower, cantaloupe, peas, peppers, potatoes, broccoli and beans, among others. Unlike trifluralin, it can be used on squash, pumpkin, watermelon, garlic, lettuce and cucumbers. This herbicide is effective for 12 to 16 weeks.
  
  

Other Controls

• Certain crops are good for suppressing weeds because they have a smothering, low-growth habit. Vegetable crops offering this benefit include squash, melons, cucumbers, potatoes and tomatoes. Many mechanical controls are also effective, including manual removal of weeds and application of mulches, which help to prevent weed emergence. Many tools remove weeds without requiring the gardener to bend over. Whatever method used, remove weeds before they reach 3 inches tall and become invasive.