Last Chance for Pre-emergents!

Please don’t call my radio program or post on my Facebook page after this weekend saying, “Neil… Is it too late to apply pre-emergent weedkillers?”

The timing I’ve settled on 25 or 30 years ago is that pre-emergent granules need to be applied between August 25 and September 5 all across Texas in order to prevent germination of winter weeds. I’m willing to slide it back to September 8 to cover this weekend, but I don’t want to give in much more. (If you’re in Deep South Texas/the Rio Grande Valley I could be talked into another couple of weeks, but nowhere else.)

Rather than just type it all out again, here is what I posted on Facebook just a few days ago. (I changed the headline.) Please read it carefully. It should answer all of your questions.


Rescuegrass on left and annual bluegrass on right. Both were extremely widespread in spring 2019.

To prevent germination of annual bluegrass (Poa annua), rescuegrass and ryegrass.
Apply DIMENSION, HALTS (NOW CALLED WEED-EX) OR BALAN granules. Yes, I could list other types. I’ve kept my list short. This topic is confusing enough.
Only one application.
This is your only chance. Once these weeds sprout and start growing you do not get a second chance. There is no spray 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.
Mow your lawn, then apply the granules, then water the soil moderately.
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.

Continued Below
Broadleafed (non-grassy) weeds, clockwise from upper left: dandelions, chickweed, henbit and white clover.

Gallery 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 broadleafed weeds like henbit, chickweed, dandelions and clover you DO get a second chance. You can apply a broadleafed weedkiller spray (containing 2,4-D) around Thanksgiving or in late winter. Read and follow label directions.

NOTE: If you have a lawn care company looking after this sort of thing for you, their timing may be slightly different. They have access to different products. They also can’t get to all of their customers on the same date just because Neil says that’s a great day to treat. If their work gives great results, we need to let them do their job.

Posted by Neil Sperry
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