- Crabgrass needs a soil temperature of 550F for about 5 days to start the germination process -
People like to use flowering plants to go by to determine when to have their pre-emergent down. This idea can give you a general time frame, but flower bud development is governed by air temperature and not soil temperature.
- Dithiopyr 2L, is capable of providing limited post-emergent control of crabgrass until the 2-3 leaf stage -
Technical Services Manager, Certified Professional Agronomist