Painful, prickly weeds are a common frustration for homeowners and pet owners. These nuisance plants produce sharp burrs or spines that easily attach to clothing, skin, or animal fur. Generally known as “sticker weeds,” these plants utilize specialized structures to ensure their seeds spread widely. Effective management requires understanding the specific species causing the problem. This guide identifies the most common offenders and explores effective strategies for their removal.
The Most Common Offenders
Coastal Sandbur (Cenchrus spinifex) and Field Sandbur (Cenchrus longispinus) are common warm-season annual grasses found across the United States. They grow low to the ground and are often mistaken for normal turfgrass before their seed heads mature. The defining feature is the small, sharp burr, which forms in clusters and is covered in stiff, barbed spines that readily detach.
Lawn Burweed (Soliva sessilis), also called Spurweed, is a cool-season annual that thrives in thin turf during the winter and early spring. It forms small, fern-like rosettes of finely divided leaves that are inconspicuous until maturity. As temperatures rise, the plant dies back, leaving behind tiny, rigid, star-shaped burrs nestled low in the grass canopy.
The stickers are formed directly from the hardened fruit and are extremely rigid. These sharp points are positioned close to the soil surface, making them difficult to spot until stepped on. The plant germinates in the fall and produces stickers throughout the winter and spring before summer heat kills the foliage.
Goathead (Tribulus terrestris), also known as Puncture Vine, is a summer annual that spreads rapidly through prostrate, mat-forming stems. Its leaves are small and opposite, giving the plant a delicate, ferny appearance that belies its painful fruit. The name “Goathead” comes from the fruit’s resemblance to a goat’s head, featuring two long, sharp spines and several smaller ones.
The woody fruit is exceptionally tough and can cause flat tires on bicycles, hence the name Puncture Vine. This weed prefers dry, sandy, or disturbed soils and is commonly found in driveways, sidewalks, and neglected garden beds. Identification is often confirmed by the presence of bright yellow, five-petaled flowers before the burrs develop.
Anatomy of the Sticker
The sharp structures produced by sticker weeds are highly evolved mechanisms for seed dispersal, a process known as epizoochory. These specialized seed casings or fruits are designed to latch onto external carriers, ensuring the plant’s progeny are transported far from the parent plant. The structures are often modified plant parts, such as hardened sepals or ovaries, that become rigid and pointed upon maturity.
The efficacy of these “stickers” lies in their microscopic architecture, which often incorporates barbs or retrorse (backward-pointing) hooks. These features function like miniature anchors, allowing the burr to penetrate and hold fast to fibrous materials like fur, clothing, or skin. Once attached, the seed casing remains in place until the carrier removes it.
The spines of Sandbur are covered in tiny, stiff hairs that increase friction and grip, while the woody fruit of the Goathead possesses robust, cone-shaped spines. This structural toughness allows the seed to survive mechanical damage and ensures widespread distribution.
Effective Management and Removal Strategies
Managing sticker weeds requires a multi-faceted approach, beginning with mechanical removal to reduce the current seed bank. Hand-pulling is effective for controlling small infestations, but it must be done before the burrs mature and drop their seeds. Wearing thick gloves is necessary to avoid injury from the sharp spines.
Once burrs have dropped, they can be removed using specialized tools like a stiff rake, a shop vacuum, or an old blanket dragged across the affected area. This physical removal is important because the burrs contain viable seeds that can remain dormant for several years. Removing the mature seed heads before they detach is the most direct way to break the weed’s life cycle.
Modifying the growing environment provides long-term control, as most sticker weeds thrive in thin, stressed turf. Raising the mowing height encourages a dense lawn canopy that physically shades out weed seeds and prevents germination. Aerating compacted soil and ensuring proper irrigation promotes vigorous turf growth, making the area less hospitable to opportunistic weeds like Lawn Burweed.
Chemical control relies heavily on proper timing, especially when utilizing pre-emergent herbicides.
Pre-Emergent Application
Since Sandbur and Goathead are warm-season annuals, pre-emergent products must be applied in the early spring before soil temperatures consistently reach 55 to 60 degrees Fahrenheit. Conversely, Lawn Burweed is a cool-season annual that germinates in the fall, meaning its application window is typically late summer or early fall. Identifying the weed’s life cycle is paramount to effective chemical intervention.
Post-Emergent Application
For established weeds that have already germinated, post-emergent herbicides are necessary. These products are generally most effective when applied to young, actively growing weeds. Selective broadleaf herbicides containing active ingredients like 2,4-D or dicamba are often used to target weeds like Lawn Burweed and Goathead without harming turfgrass.
When using any herbicide, always read and strictly follow the product label instructions. Improper application can harm desirable plants, fail to control the target weed, or pose risks to pets and local wildlife. Consistent, targeted management over several seasons is required to deplete the long-lived seed bank.