I've been inundated with questions about grass burrs lately, and that's prompted me to adapt a piece I did not long ago for a local magazine.
In our Southeast Texas soils, which range from sandy to loamy to clay, one of the most annoying weeds is one that actually thrives in the sandiest.
Some call it "grass burr" or "burr weed" or "cockleburs" or "sand spurs." Whatever they're called, they're a big pain in the sand.
So, if these weeds love sandy soils, what's a "yardener" to do? Well, while there's no silver bullet or magic herbicide, there are some cultural steps we can take to make it harder for these weeds to take hold.
It's a four-step process that begins with adding humates or humus, then using nitrogen-rich (or nitrogen-only) fertilizers, staying dedicated to a specific fertilization schedule, and gathering up as many burrs as possible.
Let's start with the humates. There are several forms of humic acid on the market, bit I prefer the granular kind that can easily be applied with a broadcast spreader. The liquid versions are just as effective, just not as cost-effective. (The liquids are more expensive because they cover less area.) Burrs hate a humate-rich environment, so apply them on a quarterly basis the first year, then one or two times every year after that.
Another thing burrs hate is a nitrogen-rich environment. I'm not suggesting you should use "high-nitrogen" fertilizers. Use nitrogen-rich or nitrogen-only fertilizers. The most basic and most cost-effective, always available at nurseries, garden centers and feed stores, are ammonium sulfate formulas that usually show an N-P-K (Nitrogen-Phosphorous-Potassium) ratio of 21-0-0. There's also Sweet Green from Nitro-Phos Fertilizers, a new organic formula that has an N-P-K of 11-0-4. It's perfectly fine for the nitrogen hit needed.
The next step is staying true to a smart fertilization schedule that calls for slow- or controlled-release fertilizers and consistent use of pre-emergent herbicides to block weed seeds from germinating. If you are not familiar with my personal fertilization schedule, designed for the Gulf Coast, check it out here. You'll find lots of lawn tips, advice, and both organic and synthetic fertilization schedules.

The final step is the one that most annoys people, and I completely understand why. It's the process of picking up as many fallen burrs as possible. The burrs are the seeds that will likely germinate again.
Now, unless you want to kick around in layers of tube socks and allow them to hitch a ride on your feet and ankles, you have to be clever. If you have a shop vacuum or wet/dry vac, suck up as many burrs as possible. You'll never get all of them, but the few left behind will be better controlled by your pre-emergent herbicide applications.
You might also try using a "tow sack" ... a burlap bag with something in the bottom to weigh it down as you hand-drag it around the area or tow it around behind a riding mower or tractor. Once one side of the sack is covered, flip it over and do another pass. Then, turn it inside out and go through the process again. Throw the bag away.
By the way, if you use the vacuum method, do the vacuuming before applying the humates and fertilizer, so you don't vacuum up all the good stuff.
All this may sound a bit tedious, but after going through the four steps you should see a remarkable difference in three to six months.
Incidentally, I'm aware that cockleburs are completely different, botanically speaking, from burr grass. I'm just including them in this advice because folks who aren't horticultural experts usually view them as the same thing.















