I want so badly to tell you it’s time to use cool-season herbicides. But we aren’t quite in the proper temperature zone yet.

These awesome tools – such as Fertilome’s Weed Free Zone and Bonide’s Weed Beater Ultra - will help reduce an infestation of weeds like Virginia buttonweed and doveweed.  But we really need our high temperatures to be 80 degrees or below, and our low temperatures need to consistently reach into the 60s, 50s or 40s.

If you’re new to the region or these garden tips, you should know that years ago … before the advent of cool-season herbicides … broadleaf weed control December through February was pretty much non-existent, because herbicides normally used in the spring and summer can actually kill St. Augustine and Bermuda lawns if used at the wrong time of year. 

But there are some caveats to be respected for these carfentazone-based herbicides to work properly.   First, we need actual autumn weather, because cool-season herbicides are most effective between 45 and 75 degrees.  If high temperatures are still in the 80s or above, cool-season herbicides have the potential to burn up grasses. They also won’t work if it’s too cold. 

Also, if you’re new to the region or GardenLine, you need to know about the importance of surfactants.   Because most of our water along the Gulf Coast is so hard, we have to help our herbicides stick to the weeds we want to kill. Adding a surfactant prevents the liquid product from beading up and just rolling off the leaf surface into the soil.  

In addition to being in the right temperature range and using a surfactant, another important point is knowing HOW to apply these products. You should use either a pump-up sprayer or a hand-held trigger sprayer. These weed-killing products are sold mostly in concentrate, but I recommend avoiding the use of dial-and-spray or ready-to-spray bottles that hook up to a hose. Spot treating is paramount with these controls … spraying them on the entire yard can cause yellow grass, and they’re not as precise as pump-up or trigger sprayers. If a ready-to-spray formula for the end of a hose is all you can find, use extreme caution and focus on spot treatment. You’ve got to be quick with the ON and OFF lever.

One final note about these herbicides: they are specific for broadleaf weeds. If you’re troubled with things like clover, you have permission to spot treat with a carfentazone-based herbicide.  But they will not control any grassy weeds.