Pre-Emergent Herbicides for Vegetable Gardens: Treflan vs. Dimension and Why Roundup Won't Stop Seeds

Gardener wants to kill grass seeds in vegetable garden before spring sprouting. Asks what to use.

Pre-Emergent Choices

• Vegetable garden: Treflan (read label—pre-plant for some crops, post-plant for others).
• Ornamentals/lawn: Dimension.

Pre-emergents form a surface barrier that kills germinating seeds. Any cultivation destroys the barrier—till/weed first, then apply.

Follow-Up: Roundup?

Roundup (glyphosate) is post-emergent only—kills plants, does nothing to seeds or soil. Replant almost immediately after spraying. It will NOT stop seeds from germinating. Use a pre-emergent, start seeds indoors, transplant.