Enjoy a beautiful lawn with the Spectracide® weed stop for lawns (AccuShot Refill) it delivers results in hours. Some hard-to-kill weeds may require re-treatment. Wait at least 30 days between applications - some weeds can take that long to die. Do not apply when daytime temperatures are above 85 deg F as lawn injury can occur. Do not water treated area within six hrs after application or apply if rain is expected that day.