What is the concern with putting pre-emergent down too early?
Once you make an application, the clock starts ticking for how long the material will last in the ground. Check your product label for the rate vs time and also consider how harsh weather conditions in the spring could affect your application.
Nitrogen could be used up too early. In May or June when soil temperatures are right for weed issues, you could already be running out of your pre-emergent control.
What can you do?
1. Wait a little bit to make your pre-emergent application
or
2. Apply now, but plan to make a half/low-rate supplemental application or move your next application closer