Few things are as annoying as walking barefoot across a lawn only to be attacked by those prickly, painful hitchhikers: grass burrs. These little nuisances cling to everything – skin, socks, your pet’s fur – making them a real pain, literally and figuratively. They’re not just annoying; they can cause skin irritation and, in agricultural settings, can injure livestock and contaminate crops, leading to economic losses.
This article is your comprehensive guide to understanding, preventing, and controlling grass burrs. We’ll cover how to identify them, the impact they can have, and various strategies for managing them, including pre- and post-emergent herbicides and helpful cultural practices.
Identifying grass burrs: Know your enemy
If you’re like me, you’ve probably had a run-in with grass burrs, maybe without even knowing what they were. These irritating plants are common in warmer climates, especially where the soil is sandy. You probably know them best by their painful seeds, or burrs, that seem to love attaching themselves to skin, clothing, and especially your poor pets.
Grass burrs are annual summer grasses, which means they sprout, grow, set seed, and die all in one season. Knowing this is key to getting them under control.
Spiny burr grass
One of the most common types of grass burrs is spiny burr grass (Cenchrus longispinus). The plant has stems, leaves, flowers, fruit, and seeds, just like any other grass. But it’s the seeds you’ll remember. The burrs are small, only about 3 to 7mm in diameter, but the spines make them mighty.
You might also hear them called sandburs or sticker burrs, depending on where you live.
The Impact of Grass Burrs: More Than Just a Prickly Nuisance
Grass burrs are more than just an annoyance you find stuck in your socks. They can have a real impact on the environment and on the economy.
Ecological and Agricultural Impacts
Grass burrs can muscle out native plants, altering the balance of local ecosystems and even affecting waterways. They also create problems for farmers, as they can lower the quality of wool and make it harder to handle livestock. Plus, they can contaminate crops, leading to economic losses.
Social and Health Impacts
Those prickly burrs also put a damper on outdoor fun. They can make parks and recreational areas less enjoyable, and nobody wants to worry about getting stuck every time they step outside. And, of course, there’s the potential for injury and discomfort – those spines can be pretty sharp!
Pre-Emergent Herbicides: Stopping the problem before it starts
Pre-emergent herbicides are designed to stop grass burrs from germinating in the first place. These herbicides create a barrier in the soil that prevents the seeds from sprouting.
Timing is everything when it comes to pre-emergent herbicides. You’ll want to apply them before the soil temperature warms up enough for the burrs to germinate. You’ll want the soil to be consistently between 52 and 72 degrees Fahrenheit. In North Texas, that typically means applying the herbicide in late February or early March, before the soil temperature reaches 55 degrees.
These herbicides generally last for 3 to 6 months.
Recommended pre-emergent herbicides
Some pre-emergent herbicides to consider are those containing the active ingredients Prodiamine and Dithiopyr.
Application tips
- Lightly water the area after you apply the herbicide. This helps activate the barrier.
- If you have a heavy infestation, you may want to reapply the herbicide every six weeks until September.
Post-Emergent Herbicides: Tackling Existing Grass Burrs
If you’ve already got grass burrs in your yard, you’ll want to consider using a post-emergent herbicide to kill the plants. These herbicides are absorbed by the plant, and they work by interfering with its growth processes. Once the herbicide starts working, you should see the grass burrs begin to wither and die.
For best results, treat grass burrs when they’re young, ideally when they’ve grown just two to four leaves.
A number of post-emergent herbicides can be effective against grass burrs. Look for products containing these active ingredients:
- Glyphosate
- MSMA (monosodium methyl arsenate)
- Imazaquin
Liquid herbicides tend to provide better coverage than granular ones, so opt for a liquid if you can. After applying the herbicide, be sure to water your lawn properly to help the herbicide soak into the soil and reach the roots of the grass burrs.
Cultural and organic control methods: A holistic approach
You can manage grass burrs with a combination of good lawn care practices and organic options.
Lawn maintenance
One of the best ways to prevent grass burrs is to cultivate a thick, healthy lawn that can naturally resist weeds. Proper watering and fertilization are essential. Most grasses thrive in soil with a pH between 6.0 and 7.0, so consider having your soil tested and amended as needed.
Mowing can also play a key role in managing grass burrs. Mow frequently and mow low, especially during the burr’s growing season. You may need to mow twice a week at first. Using a mower bag can help collect the seeds before they have a chance to spread.
Organic options
If you prefer organic methods, you can try using an herbicide made from orange oil. These are most effective when applied between May and July, when the burrs are actively growing.
You can also physically remove the burrs. This can be time-consuming, but it’s an effective way to get rid of them without using chemicals.
Combining Strategies and Special Considerations
For the best results, it’s important to combine pre-emergent and post-emergent herbicides. You’ll also want to follow good lawn care practices like mowing, watering, and fertilizing correctly.
If this sounds like too much, consider calling a professional lawn care service.
Pro Tip for Texas Lawns: Because of our climate, Texas lawns often need special attention. Get local advice about which herbicides to use and when to apply them. Your county extension office can help!
Closing Thoughts
Getting rid of grass burrs takes a multi-pronged approach. The best way to win the battle is to prevent them with pre-emergent herbicides, control them with post-emergent herbicides, and use good lawn care practices to keep your grass healthy.
Don’t delay! Take action now to get rid of grass burrs and enjoy your lawn.