Sandspur or sandbur (Cenchrus) is a type of annual weed that can grow thorny and painful spikes. These prickly nuisances can hurt if they come in contact with you. The sandspur weed is registered in 46 states of the U.S. as a noxious weed. It originally belongs to the Poaceae family and looks like normal grass earlier in the year until it becomes a dangerous weed.
This weed can be found mostly in the southern parts of the U.S. and other areas including California or Washington D.C. Perennial sandbur is another species of this weed that overwinters and is found in various areas like Texas, Oklahoma and New Mexico. Although sandspur can grow in almost every kind of soil, they usually grow in dry and sandy soils. This is also the reason for their name.
Sandspur seed usually germinates during the spring and continues through the summer. The weed can grow up to 2.5 inches long in most cases and form clusters on the ground. These clusters can impact the movement or mobility of individuals passing by. They can sprawl along the ground or exist in ascending order. Naturally, these weeds exist in sandy fields and large open areas. You may also find them in large abandoned areas.
Sandspur Non-Chemical Control
Controlling weeds through cultural or non-chemical methods requires taking care of your lawn regularly. This includes mowing, watering and fertilizing it properly. You need to aim for a dense and vigorous lawn as the first step. Increasing the density of your lawn will help reduce sandspur growth as it becomes increasingly more difficult for the weed to compete with turfgrass for space and sunlight. If there are bare areas throughout the lawn, sandspur has the chance to grow and thrive in these locations. Mowing your sandspur infested lawn will prevent seed heads from growing to reduce opportunities for it to emerge again next year. Find out which height you should mow your lawn at in our Lawn Mowing Guide.
Finally, proper fertilization of the lawn can help it develop a healthy canopy that is thick enough to crowd out weeds. Here are some of our favorite fertilizers. You can learn more about them in Why Use Lawnifi Fertilizer?.
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Sandspur Chemical Control
Chemical control products can be effective against sandspur and both pre- and post-emergent herbicide options are available. A pre-emergent, as its name suggests, controls weeds before they germinate and appear in your lawn. Post-emergents, on the other hand, are products that control currently existing weeds.
Pre-Emergent Control of Sandspur
Sandspur pre-emergent herbicides can only work efficiently before the seed germinates, so it’s more of a preventive method. One pre-emergent option that can be applied is Dimension by Dow AgroSciences (active ingredient: Dithiopyr). This product is mixed into a spray tank for easy application across a specific area or an entire lawn and can provide season long control of weeds.
Dimension 2EW$149.95 – $649.95
Another great pre-emergent for sandspur is any prodiamine-based weed control product. Options range from liquid Prodiamine 65 WDG to granular Crabgrass Control Plus 0-0-7 with 0.37% Prodiamine. A 5-pound bottle of Prodiamine 65WDG covers between 50,000–80,000 sq. ft. and requires tank mixing before application. A 50-pound bag of Crabgrass Control Plus 0-0-7 with 0.37% Prodiamine covers 12,500 sq. ft. and requires a broadcast or drop spreader for application.
Another effective pre-emergent for sandspur is Hi-Yield Atrazine. Both St. Augustine and centipede grass types are sensitive to active ingredients like 2,4-D and MSMA, so Atrazine-based weed control products are safer to use on these grass types if applied appropriately. Hi-Yield Atrazine has pre- and post-emergent properties. Pre-emergents should be applied during the early spring and late fall for effective control. Read product labels thoroughly before application.
Hi-Yield Atrazine Weed Killer$16.95 – $19.95
Post-Emergent Control of Sandspur
One of the top-recommended post-emergent weed control products for sandspur is Celsius WG by Bayer (active ingredients: Thiencarbazone-methyl, Iodosulfuron-methyl-sodium, and Dicamba). This product can be applied as a broadcast application or a spot treatment by a backpack sprayer and has a lower risk of damaging turfgrasses in high temperatures when compared to other herbicides.
As previously stated, Hi-Yield Atrazine is a great post-emergent option for St. Augustine or centipede lawns. This weed control product has pre- and post-emergent properties.
Hi-Yield Atrazine Weed Killer$16.95 – $19.95
If you decide to use a chemical control to stop your sandspur problem, make sure you read the label carefully to ensure that it will not cause any damage to your lawn and is compatible with your grass type.