porkpal said:As I understand it, you have to treat them early (when the soil is 70 degrees) or success will be minimal.
If I remember correctly (it's been a while) we sprayed the fields the first application sometime after the last frost and then a second application when the grass was "greening" up, but before any seed heads appeared.
If this is not treated it will only get worse and it can spread like wildfire. Even animals walking through will pick the grass spurs and spread them elsewhere.
