Japanese Stiltgrass Invasion--Maryland Lawn
Can you recommend a pre-emergent herbicide that will prevent Japanese stiltgrass from germinating? Stiltgrass has invaded over 50% of my quarter-acre residential lawn, so we're beyond spot-treatments and weed pulling. I've tried crabgrass preventers in previous years without success. Stiltgrass appears to be a significant problem here in southern Montgomery county lawns. Thanks for any recommendations you can offer.
Montgomery County Maryland
You are spot on and not alone. Japanese stiltgrass has become hugely invasive in many parts of Maryland.
Here is our page about it: https://extension.umd.edu/hgic/topics/japanese-stiltgrass
It is an annual weed which is a prolific seed producer, so preventing seed production by mowing, etc., is part of a good control program. Like most weeds it will take advantage of thin turf and germinate there, so overall lawn management- mowing high etc. is also important. (https://extension.umd.edu/hgic/topics/tips-lawn-weed-prevention-and-management)
Japanese stiltgrass is shallow rooted and is therefore relatively easy to pull, which is possible in a new infestation. For one like yours, you are on the right track with pre-emergent applications like those for crabgrass, but it needs to be applied earlier- see link above.
Fenoxyprop is another option, also covered above.