You should wait about 4 weeks after applying weed and feed before overseeding your lawn. The herbicides in weed and feed products can harm new grass seeds and prevent them from sprouting, so this waiting period allows the herbicides to work on the weeds and then fade away, making it safe for seed germination
. Additional relevant points:
- The lawn can usually be overseeded 3 to 4 days after applying a general lawn fertilizer, but weed and feed products require a longer wait-about 4 weeks
- Avoid applying weed and feed too soon before or after overseeding, as new grass is vulnerable and herbicides can kill it. If you want to feed the lawn while overseeding, use a fertilizer without herbicides
- The best times to overseed are spring and autumn when temperatures are consistently above 13ºC, which supports optimal germination
- If you have already overseeded, wait until the new grass is well established before using weed and feed again, typically at least a month later
In summary, to overseed safely after using weed and feed, wait approximately 4 weeks before planting seed to ensure the herbicides have dissipated and will not damage the new grass.
