The sandbur is a type of grass known for its painful, spiny seed pods. This weed’s ability to quickly spread and its sharp burs make it a major problem for homeowners, recreational areas, and agriculture. The plant is a member of the genus Cenchrus, often called bur grass or hedgehog grass, and its presence can quickly degrade the quality of lawns and pastures. Dealing with sandburs requires both immediate action to remove the burs and long-term strategies to eliminate the plant.
Biological Characteristics of the Sandbur
Sandburs are warm-season grasses that can be either annuals or, in some species and mild climates, short-lived perennials. The plant often resembles other grasses when young, with thin, flat leaf blades generally less than a quarter-inch wide. A key characteristic for identifying the plant is the light-colored, hairy leaf collar where the blade meets the stem.
When the plant matures, it produces a specialized flowering structure, known as an inflorescence. This structure holds the bur, which is a hard, spherical or oval casing protecting the seeds inside. The bur is covered in numerous stiff, needle-like spines that aid in seed dispersal by catching onto fur, clothing, or skin. Germination begins in the spring when soil temperatures reach approximately 52 degrees Fahrenheit, and burs are produced from early summer until the first frost.
Where Sandburs Thrive
Sandburs are widely distributed across warm and temperate regions globally. True to their name, they exhibit a strong preference for dry, sandy, and nutrient-poor soils, often found in coastal areas, sandy fields, and poorly maintained lawns. They are highly successful at colonizing sites where desirable turfgrasses struggle to survive due to lack of water or thin growth.
Sandburs are opportunistic weeds that flourish in disturbed or sparse ground, such as roadsides, thin patches in turf, and unmanaged pastures. The burs’ protective coating allows the seeds to remain viable in the soil for several years. This persistence means that once an area is infested, the weed can re-emerge season after season if soil conditions remain favorable.
Safe Removal of Sandburs from Skin and Clothing
Immediate removal of sandburs is necessary to prevent pain and possible infection. For burrs embedded in human skin, first wash the area gently with soap and water. Small, shallowly lodged spines can often be removed using fine-tipped tweezers, ideally with a magnifying glass to ensure complete extraction. After removal, clean the puncture site again and apply an antiseptic ointment to prevent infection.
Removing sandburs from pet fur, especially from paws and between toes, requires patience and caution. For lightly attached burs, a hard-pin slicker brush or a metal comb can be effective, working slowly from the end of the hair toward the skin. Severely matted or entangled burs may benefit from a small amount of vegetable or coconut oil rubbed into the area to lubricate the spines and loosen their grip. If a burr is deeply embedded or the animal is in pain, a veterinarian should perform the removal to avoid injury.
Burrs caught in clothing can be removed using several household tools and techniques. Duct tape or a strong adhesive lint roller pressed firmly over the fabric will lift many surface-level burs and spines. For deeper, more stubborn burrs, a stiff-bristled brush or a fine-toothed comb can be used to carefully scrape them out of the fibers. Always check clothing, especially socks and shoes, thoroughly before washing to prevent damage to a washing machine or transfer to other garments.
Controlling Sandbur Infestations
Managing sandbur populations requires a two-pronged approach: cultural and chemical control methods. Cultural control focuses on creating a dense, healthy turf that outcompetes the weed. Mowing the lawn at the proper height for the grass species and providing consistent irrigation and fertilization can help choke out sandbur seedlings. Hand-pulling is a viable option for small infestations, but it must be done before the plant sets seed to prevent further spread.
Chemical management typically relies on pre-emergent herbicides, which are the most effective tool for long-term control. These are applied in early spring to create a chemical barrier that stops the sandbur seeds from germinating. Post-emergent herbicides are used to treat existing plants and are most effective when applied to young, actively growing sandburs before they produce mature seed heads. Since sandbur seeds can remain viable in the soil for several years, a consistent pre-emergent program over multiple seasons is necessary to fully deplete the seed bank.