Rain is very beneficial following a Pre-Emergent, Fertilizer, Lime or Grub treatment. Moisture will not affect the results of these cycles. Herbicide applications can be potentially affected in “Heavy Rain Conditions”. It typically takes around 14 days to see the weeds wilt and die. If it has been 14 days and your not seeing results, please give us a call and we will schedule a re-treatment at no additional cost to you!