Definition: A chemical weed killer applied prior to the emergence of the weed from the soil. Prevents weed seeds from germinating.
Also Known As: pre-emergence herbicide
Alternate Spellings: preemergent
Examples:
Chemicals like dithopyr (Dimension) and pendimethalin (Lesco's Pre-M) prevent all seeds from germinating. Grass seed cannot be applied for 6-12 weeks after application.
Siduron (Tupersan) prevents only weed seeds from starting, allowing grass seed germination.
Corn gluten is an organic product with pre-emergent characteristics.
