Nobody likes having burr weeds in their yard. The spiky balls they leave in your grass are a painful surprise for bare feet. And they’re a nuisance when they stick to clothes and animal fur.
Burr weeds can quickly take over your yard if you leave them. The spiky burrs are actually seed pods, and the weed easily spreads. But they can be difficult to eradicate.
So in this article, I’ll show you how to get rid of burr weeds. And how to keep them away once you’ve killed these annoying plants.
Taking Action At The Right Time
Southern Sandspur (Cenchrus echinatus)
Getting rid of burr weeds is a lot easier if you deal with them at the right time. When you notice your lawn covered with small spiky balls, it’s already too late in the year to fully deal with them.
The burrs contain the weed seeds. After germination, the weeds grow rapidly, flower, and then produce their small spiky seed pods — the burrs. As the plant matures, the burrs drop to the ground, or are spread by animals and on clothing.
Even if you kill the plants that are currently growing, the burrs contain seeds. And depending on the type of burr weed, the seeds will germinate in the spring or the fall, producing more burr weeds. And creating an even bigger job for you.
So ideally, you want to get rid of burr weeds before they set seed. But you can still reduce the problem even after the seeds have spread.
Using herbicides to get rid of burr weeds is best done in two stages:
Using A Pre-emergent Herbicide
If the sticky burrs have already spread, then it’s a good idea to use a pre-emergent herbicide.
Pre-emergent herbicides prevent weed seeds from germinating in the soil. But you have to use them at the right time of year. This means identifying the burr weed that’s growing in your yard. And finding out when the seeds germinate. Usually, you’ll apply the pre-emergent herbicide in either early spring or fall.
Lawn Burweed (Soliva sessilis) and burr medic (Medicago polymorpha) are common types of burr weeds that germinate in the fall and grow during the winter. Before flowering and producing sticker burrs in the spring. So use a pre-emergent in the fall to stop the seeds from germinating.
If you have sandbur growing on your lawn, then the seeds germinate in the spring. So apply the pre-emergent in early spring before the soil heats up above 50 C.
You can use chemical pre-emergent herbicides that include active ingredients such as isoxaben. Or you can use a natural pre-emergent herbicide like corn gluten meal.
But don’t apply the herbicide to newly seeded areas of your lawn because it will prevent the grass seed from germinating as well.
A pre-emergent applied at the right time of year will prevent most burr weeds from sprouting. But some weeds might still emerge. So watch for them during the growing season. And spot treat any weeds that grow with a post-emergent herbicide before they spread their burrs.
Using A Post-emergent Herbicide
Post-emergent herbicides come in two types: non-selective and selective.
Non-selective herbicides kill all plants that you spray them on. So you need to be careful when using them around your lawn and desirable plants.
Selective herbicides are formulated to kill broadleaf weeds and some grassy weeds. Leaving your turfgrass unharmed. Selective herbicides are a better choice for getting rid of burr weeds that are growing in your lawn.
Removing Burr Weeds By Hand
It may take some effort, but removing burr weeds by hand can be the best way to get rid of them. Particularly if you don’t want to spray chemicals in your yard.
But it does take time. And it’s most practical for small weed infestations.
Before you start, it’s a good idea to get a pair of gardening gloves that are suitable for prickly weeds. This will protect your hands if you accidentally grip around any spiky burrs.
Water the soil around the weed to make it softer. This makes the burr weed easier to pull out of the ground. Then grab the weed at the base of the plant and twist and pull to lift it out. Make sure you take all of the roots as some weeds can regrow from pieces left in the soil.
To make the job easier, you can use a garden shovel to dig around and under the burr weeds and lift them out of the ground.
Once you get rid of burr weeds that are growing on your lawn, one of the best ways to keep them away is to practice good lawn care.
Burr weeds find it easier to invade thin and patchy turf. And having a thick and healthy lawn can crowd out burr weeds. So fertilize regularly with a nitrogen rich fertilizer.
Mowing also helps. Set the mower blade to 3-inches. This shades the soil surface, preventing weed seeds from getting the sunlight needed to sprout. And letting the grass grow a bit longer promotes a strong and deep root system because the longer blades photosynthesize more. Both of these factors make it harder for weeds to become established.
You can often control burr weeds by regular mowing, as this removes the flowerheads before they have a chance to produce seeds. But it won’t eliminate the weeds, and they can grow back.
What About The Spiky Burrs In The Grass?
If you already have grass stickers in your lawn then try dragging a woolen blanket over the area several times. Many of the burrs should stick to the blanket, reducing the number left in the grass.