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Field Sandbur (Cenchrus longispinus)

Crop Impacts: Pastures

Field Sandbur 1

About Field Sandbur:

Field Sandbur is an aggressive, summer annual weed. Immature Field Sandbur is a good food source for livestock. That being said, as this grass matures it produces stiff spiked fruit that can injure the mouths of livestock. This weed will grow until the first hard frost or freeze of the fall season.

Family: Grass family (Gramineae)

Field Sandbur 2 Field Sandbur 3

Field Sandbur Scouting and Prevention:

As a seedling, Field Sandbur has flattened seed leaves with a slight purplish tinge at the bottom of the plant. For a mature plant they often create large mats that can grow up to 2 feet long. They have straight branches and stems, and lay along the surface of the ground with loose spikes of burs near the tops of the branches. The seeds germinate from within the bur which contains 1 to 3 seeds per bur. The burs contain flower clusters that have been enclosed in spiny leaves. There are about 20 to 50 burs that will occur on 1 spike. These burs are light brown when they are fully mature and begin to flower during the months of July to September.

Common locations

  • - Sandy soil
  • - Well-drained soil
  • - Fields
  • - Alfalfa fields


Pre-emergent herbicide management works well when sprayed with prowl H2O at 1.1 to 4 quarts per acre. It is important that the pastures being sprayed with this pre-emergent herbicide is dormant, meaning it cannot be applied to newly planted pastures. After prowl H2O has been applied, it must be activated by irrigation or rain; if not, the herbicide will fail. With this herbicide you are not allowed to have livestock graze on it for 45-days and for 60-days you cannot hay sprayed areas. Apply the pre-emergent when the soil reaches 11°C to create the most impact.

Field Sandbur Control:

Cultural Control

The best way to ensure this weed does not entirely take over your lawn and to also contain it is to use cultural practices such as watering, fertilizing and mowing in a time and manner that will benefit the grass, rather than the weed. A few“deep-soaks” of water will maintain a dry surface layer that gives the grass a competitive edge. Light, frequent watering will encourage shallow-rooted seeds and weeds to germinate.

Chemical Control

Post-emergent herbicides such as MASMA or DSMA provide good control for Field Sandbur when it is a young plant. It is important that you apply this herbicide only 2 to 4 weeks before Field Sandbur will likely germinate with all lawn clippings and leaves removed from the area being sprayed. Immediately after the post-emergent herbicides have been applied, it must be irrigated to help move the chemical into the soil.

Latin / Alternative Field Sandbur names:

  • - Cenchrus longispinus
  • - Bur grass
  • - Grassbur

Additional Field Sandbur Resources