<H1>Preemergence Herbicide Timing</H1> <P><UL> <LI><H2>Soil temperatures can vary in a neighborhood - south facing slopes warm earlier in the Spring </H2> </UL><UL> <LI><H2>Coarse textured soils warm more quickly than fine-textured soils </H2> </UL><UL> <LI><H2>Most preemergence herbicides are degraded by soil microorganisms - activity is less at 45 degree vs. 70 degree soil temp. Most warm-season grassy weeds germinate at 55 to 65 F. APPLY EARLY </H2> </UL><UL> <LI><H2>Can the site be irrigated for activation?</H2> </UL></P> <P></P> <P>