The air temperature is in the mid 60s, and already the weeds started to germinate. Is this a good time to spray a pre-emergent herbicide or is it too late? Should I apply a post-emergent herbicide instead? Can I apply both together? I want to make sure the application is done properly.
The rule of thumb for pre emergent weed control is to apply between forsythia bloom and Lilac bloom.
You can apply post emergent any time you see weeds.
This article will explain - http://www.grassstitcher.com/lawn-care-info/lawn-care/lawn-weed-control/