It’s that time of year to apply fall pre-emergent weed killers for those tough-to-kill grassy weeds. Personally they don’t bother me but hey, they may bother you, so let’s get started talking about how to get rid of them. We all tend to have a few grassy weeds in our lawns and gardens each year so if you are battling them, here are some helpful recommendations.
Let’s get right to the point. In order to prevent germination of annual bluegrass (Poa annua), rescuegrass, ryegrass and others, you can apply products like Dimension, Weed-ex or Balan granules. Yes, I could list other types, but I’ve kept the list short because this topic is confusing enough. Only one application will do the trick but you need to make it in the first two weeks of September for optimum control, on an average year. The weather plays a huge role in when these grassy weeds start to appear so pay attention to it or ask an expert. So this is your only chance because once these weeds sprout and start growing you don’t get a second chance.
There is no product to kill them later without harming your lawn. These granules can be used on any type of grass as long as it has been through one winter. They can be used beneath trees too.
Mow your lawn, apply the granules, then water the soil moderately to get the herbicide down where it will do some good. Yes, only one treatment will be needed. Note that these products often are labeled as “Crabgrass Preventer.” They’re the same products we apply in spring and again in early summer to prevent germination of crabgrass and grassburs, but this time we’re using them only for winter weeds. This treatment will do nothing to help with grassburs or crabgrass as that is something you will have to tackle in the spring with one of the pre or post emergent herbicides.
Now let’s talk about those broadleaf weeds — you know, the non-grassy weeds. Gallery is a good product that can be applied if you have a history of broadleafed weeds. It’s a pre-emergent weedkiller that also must be applied before they germinate. If you decide to use Gallery, apply it one day after the treatment with one of the products above, then water again. With broadleaf weeds like henbit, chickweed, dandelions and clover, you do get a second chance. You can apply a broadleaf weed killer around Thanksgiving or in late winter and it normally does a great job getting rid of those unwanted weeds.
If you have a lawn care company looking after this sort of thing for you, their timing may be slightly different and remember they have access to different products which may have different timetable than yours but hopefully with the same lethal affects on those unwanted weeds. When applying any herbicide always read and follow label directions as the label is the law. Good luck with your lawn weed battles this fall and let me know if I can help you.
Marty Morgan is Cooke County Ag Agent for the Texas A&M AgriLife Extension Service. Reach him at 940-668-5412 or firstname.lastname@example.org.