Thom from Prescott, Az writes
Dimension 2EW is a pre-emergent herbicide, so it is best applied before soil temperatures reach those that are optimal for the weeds you are targeting. This is generally before soil temperatures reach 55 degrees in the Spring. You should not apply when there is snow on the ground or temperatures are below freezing. In the Fall, you would want to apply before soil temperatures cool to those favorable for these weeds, usually below 70 degrees. We recommend contacting your local Cooperative Extension for the best recommendation on timing in your area.
Answer last updated on: 07/13/2023