Chamberbitter Is a Terrible Nuisance

Q: What do you suggest as a good solution to the weed that some people call chamberbitter? It’s attacking our lawn fiercely.

A: Chamberbitter is a terrible nuisance. One habit that makes it worse than other weeds is that it’s tropical in nature, so it germinates in early summer rather than in spring like we’re used to. It shows up in July when the best way to control it has already passed.

You have two options: spray with chemicals or hand-pull. A preemergent chemical applied in April and early June will go a long way toward controlling this nuisance weed. The most effective chemicals to apply are atrazine and isoxaben. Atrazine is labeled for broadleaf weed control in centipede and St. Augustine lawns. Isoxaben can be used on other lawn grasses.

Once chamberbitter has sprouted, use a broadleaf weedkiller with four ingredients, like 2,4-D, dicamba, mecoprop (MCPP), sulfentrazone, or calfentrazone.