MID to LATE-SUMMER CRABGRASS CONTROL TIPS (from the Red Hen FAQ Vault – The 2019 Update)

Crabgrass Photo by Michigan State University Extension

Crabgrass Photo by Michigan State University Extension

Getting right to crabgrass … it’s looking to be bad this year! From site visits and talking to quite a few landscapers and customers, with the sporadic weather / precipitation patterns this year, I believe that non-irrigated lawns are seeing the most dramatic turf-decline this year, and on a related note, the brunt of crabgrass germination. We have definitely seen a lot of customer photos this year of grass-type weeds in general.

The best way to control crabgrass is to maintain a dense, healthy turf. That way, your grass is more likely to out-compete crabgrass (and other weeds), preventing weeds from establishing. On the other hand, crabgrass tends to have rigorous survival and reproductive capabilities.

So, for lawns, it may be unrealistic to expect a crabgrass-free lawn (BUT YOU CAN TRY!)

It may be that, in the end, you will have to accept a few crabgrass plants.

Are you dealing with crabgrass at this point in the year?

Do you want to get this weed under control?

If so, we recommend following of these 2 Options to hopefully put you in a better position by next spring:

Option 1. Let the crabgrass go for now, and wait until fall and let Mother Nature kill it off. After mid-July, crabgrass plants are usually too large to control effectively. Crabgrass begins flowering and setting seed in July and will die out with the first major frost. It will take a while for these plants to decay, but at least you won’t see any in the spring. That is, unless you have allowed the crabgrass to go to seed this year, in which case you will be dealing with those seeds germinating next spring.

Option 2. As Purdue Extension points out, “Proper fertility, mowing, and irrigation is essential for crabgrass control; consider herbicidal control only if necessary.” If you are not able to tolerate the crabgrass in your lawn, we specifically recommend using a product that we carry called Q4 (CLICK HERE to read the label). Here at Red Hen Turf Farm, we really like a product called Q4 because it covers all 3 major types of undesirable weeds all in one bottle — grassy weeds, broadleaf weeds, and sedges. If there was only one herbicide product that I could use on my lawn, it would be Q4.

8/29/20 UPDATE:  You might also give Tenacity a shot (as long as the crabgrass is at the earlier smaller stage of no more than 3-4 tillers), and can read more about that option HERE.

For better crabgrass and broadleaf weed control next year, you’d really need to do some strategizing over the next few months.

For example, by adding 25-0-10 fertilizer to your lawn two times from now until winter, this should make your lawn much less weedy going into the 2020 growing season.

WHY IS THIS? The thicker and stronger your grass is grass is, the better your grass can out-compete weeds. Regular fertilizing is one of the important steps towards making that happen.

Have you ever wondered why is it that we don’t see a lot of fertilizer commercials in the fall, like we do in the spring?

My guess is that the marketing teams for the big name brands do not use turf science, but are instead driven by the purchasing habits of homeowners (for better or worse).

Our job at Red Hen Turf Farm is always to strive to save our customers time, money, and/or both. So, let’s use some turf science and feed your lawn when it needs it the most.

If you told me that you only wanted to fertilize 1 or 2 times each year, you might expect I’d recommend doing it in the spring, but actually that’s not the case.

In fact, you would get the most bang for your buck by fertilizing in September and then again in November. Are you surprised? We wrote a blog about this very topic that you might want to check out by CLICKING HERE. We have also written quite a bit about crabgrass in the past, which you can read by CLICKING HERE.

And guess what? It’s all based on turf science, with Purdue Extension as a major source that we consult, and we always recommend that our customers do the same.


8 thoughts on “MID to LATE-SUMMER CRABGRASS CONTROL TIPS (from the Red Hen FAQ Vault – The 2019 Update)

  1. Thanks info has been very helpful I have a larg yard 5 acres but it is beautiful will do more work in the fall thanks

  2. Thanks for the info, but since I live in Central Florida, we may not get the necessary frost to kill the crabgrass. We do have a lawn service to fertilize etc. but not sure why we got so much crabgrass this year.

    • Hi, thanks for asking! So, while we are well-familiar with our area’s turfgrass issues / solutions and resources for troubleshooting, when assisting people from other areas, we highly recommend you refer to / contact your state’s Extension University / Turfgrass Science department (here’s your’s in Floriday – https://turf.ifas.ufl.edu/contact_us.shtml) and/or area sod farms who should be able to better answer your question. Different soil types, common grasses, etc can make a real difference in the approach you should take. Hope this helps! – Lisa, Red Hen Turf Farm, New Carlisle, Indiana

    • Hi, thanks for asking. Here’s the LABEL for Q4, which is always good to refer to when wondering questions like this – https://natseed.com/pdf/Q4%20Label.pdf
      The label indicates, for instance:
      “DO NOT apply Q4 Turf Herbicide … to the following: … St. Augustinegrass” – so it looks like you’d not want to use it if you have St. Augustinegrass

      Also, Table 3 Use Rates for Broadleaf Weeds in Turf indicates that you can us it with Zoysiagrass, but only when fully dormant.

      I’m not sure what state you’re writing from, but we’d recommend referring to your state’s Extension University for recommendations, and you might try contacting a sod farm in our area for their recommendations. Thanks for your question! – Lisa, Red Hen Turf Farm

  3. We need help! Bought our home 18 months ago. The lawn seems to have been neglected for a looong time. We also had the yard torn up during patio work. In April we seeded very large bare spots. They grew great! Then came the crab grass and such in the sunny spots. (Shady spots are still lovely green grass). Now we have an even worse lawn than we started with. My goal is an ok lawn. I don’t mind clover or violets but the crab grass is ugly and hard under feet. Should we Q4 the whole thing now (late August) plus fertilize September and November? (Southwest Ohio).

    • Hi, good question. Generally speaking, you could use something like Q4 or Tenacity (check out THIS ARTICLE that dicusses Tenacity for Crabgrass control: https://redhenturf.com/blog/index.php/what-a-pain-in-the-crabgrass/).
      However, once it has grown beyond a small plant and has more than 4 tillers, crabgrass is very hard to control with herbicides. This article has a photo of what a “tiller” is – https://blogs.k-state.edu/turf/postemergent-crabgrass-control/

      The labels of both Q4 and Tenacity will tell you that they are only effective if the crabgrass is small and has fewer than 4 tillers. (TIP: You should always read the labels of any product you put down on your lawn.) Q4 Label: https://natseed.com/pdf/Q4%20Label.pdf … Tenacity Label: https://www.domyown.com/msds/Tenacity_Herbicide_Label_2020.pdf

      Temperature is also a factor, as both labels will describe. Once you get a nice frost, this will kill off crabgrass (for now), and give you an opportunity next spring to more effectively control the next round by using PRE-emergent / preventer herbicides that prevent the seeds from coming up in the first place, which is often the better way to go. It’s much easier to focus your efforts to control crabgrass in early spring. You may want to plan to do a fertilizer application with crabgrass pre-emergent in early spring once it’s warm enough and then even do your next application with the same type of product. It might take a few seasons to completely get it controlled depending on how much crabgrass seed is in your soil, waiting for a chance to grow. Timing is so important when considering how to best get that pesky crabgrass under control! Hope this helps. Thanks for asking!

Leave a Reply

Your email address will not be published. Required fields are marked *