Organic

• Use Preen Vegetable Garden Weed Preventer for a natural, chemical-free solution. The active ingredient is corn gluten meal. It's safe for use around all vegetables, shrubs, trees and flowers. Begin application when your vegetable seedlings have true leaves and are at least 2 inches tall.
  
  

Synthetic

• Preen's other products include Preen Garden Weed Preventer, Preen Weed Preventer with Brilliant Blooms Fertilizer and Preen Garden Weed Preventer Plus Plant Food. The active ingredient for all three is a pre-emergent herbicide called Trifluralin. These products are very specific to proper application time and rate for any given crop.
  
  

Caution

• For any herbicide, always follow the label directions for proper use, and store the product out of the reach of children and pets.