Mark from Palm Beach Fl writes,
Bayer's Celsius Has Little Effect oN Crabgrass
I have tried Bayer's product Celsius (WHICH YOU SELL) in my South Florida st aug lawn on post emergent crabgrass. It is my belief (and many others) that this product is falsely advertised. The only product that truly kills crabgrass is Asolux
Cesius is only labeled to control Large Crabgrass and there are other varieties such as hairy and smooth that are not on the label as listed weeds it will control. That could be why some are not having the success they would when using for the specific type of crabgrass they have. Unfortunately, we are unaware of a selective post-emergent herbicide to control crabgrass in a St Augustine lawn. St. Augustine is a very fragile grass, and so most selective products that are labeled to remove crabgrass and not harm your grass. It is recommended to kill the crabgrass with a round up type product, like GlyPhoSel Pro, which will also kill just the St. Augustine around the crabgrass that it is sprayed on, and then a couple weeks later re-seed those areas with new St. Augustine.
For long term control though, you should apply a pre-emergent in the late fall and early spring which will prevent new crabgrass from coming up next year. If you apply pre-emergent every year, you should not have issues with crabgrass long term. Dimension 2EW is one of our most popular pre-emergents for crabgrass.
Answer last updated on: 10/02/2014