Grass bur (sticker bur) and Crabgrass Control
Many ask for help with grass burs/sticker burs/sand burs/sand spurs and also crabgrass.
These are annual grassy weeds that germinate in the spring, grow during the early summer, then start producing the seedheads and burs you know all too well by mid-summer until frost.
The burs with grass burs are the plants’ seeds for next year, so once you have the burs forming, you know you’ll have the weed again the following year.
Here are the critical facts:
• We have no post-emergent weedkiller that will kill them in existing turf without killing the “good” turf at the same time. (This is where we used to use MSMA.)
• That means that your ONLY option will be to apply PRE-emergent weedkiller granules BEFORE the seeds sprout in the spring. The timing will vary with where you live, but the benchmark is to apply the granules one to two weeks before the average date of your last killing freeze. I will use DFW as my example. Since the average last killing freeze falls around March 17-20, that would mean that the proper time to apply the granules would be March 5-15. You would be treating earlier if you’re in South or South Central Texas. You would be applying later if you are in North Texas.
• You MUST make a second application 90 days (we’ll say 3 months) later. So in DFW, that treatment would be June 5-15. The granules are effective for about 100 days, so the second treatment is essentially a “booster shot.” If you fail to make the first treatment, the second one will be of no value.