Fireweed is a nuisance weed that pops up every spring in Georgia. This rapidly growing weed has a shallow root system and germinates in the thatch layer of lawns. Although easily controlled by post-emergent herbicide treatments, pre-emergent treatments have no effect on this invasive weed. Proper lawn maintenance practices provide the most effective means of control. Weekly mowing with a sharp mower blade at the proper mowing height will minimize Fireweed infestations. Managing your thatch layer is also important. Compacted soil and improper mowing practices can lead to excessive thatch. Spring core aeration will relieve compaction and help manage your thatch layer.