Spurweed, also known by the common names Lawn Burrweed or Sticker Weed, is a problematic winter annual broadleaf plant that can quickly turn a comfortable lawn into a painful hazard. This weed germinates in the cooler temperatures of the fall and grows unnoticed throughout the winter months, only to produce sharp, spiny seed capsules in the spring. Controlling this aggressive intruder requires a precise understanding of its life cycle and a targeted management plan.
Identifying the Weed and Its Life Cycle
Spurweed is a low-growing, mat-forming plant that often goes undetected because it stays close to the soil surface. Its leaves are small, finely divided, and parsley-like in appearance. As a winter annual, it completes its entire life cycle from seed to seed production during the cooler months.
Germination begins in the late summer or early fall, allowing the plant to establish a small rosette of leaves throughout the winter. As temperatures warm in the late winter or early spring, the plant initiates rapid growth and produces tiny, inconspicuous flowers. The notorious “sticker” is the mature seed capsule, or burr, which forms after flowering and contains the seeds for the next season. The plant dies shortly after the burrs mature, leaving the sharp, persistent seed structures scattered throughout the turf.
Non-Chemical Management Techniques
A strong, dense lawn is the most effective defense against spurweed, as healthy turf naturally outcompetes weeds by limiting their access to sunlight and moisture. Proper lawn care practices—specifically deep, infrequent watering and appropriate fertilization—encourage the turfgrass to thicken, creating a dense canopy that suppresses weed germination. For warm-season grasses like Bermudagrass, raising the mowing height in the fall helps create a thicker layer of grass to shade the soil and prevent seeds from establishing.
Manual removal is a practical option for small infestations, but timing is crucial. The entire plant must be pulled from the soil before it develops its hard, spiny burrs in the spring. Once burrs have formed, pulling the plant may scatter the mature seed capsules, effectively sowing seeds for the following year. Hand-weeding is best performed during the late fall or throughout the winter when the plant is small and the soil is moist.
Targeted Herbicide Application Strategies
Chemical control relies on a two-pronged strategy using both pre-emergent and post-emergent herbicides, where timing is the most determinative factor for success. Pre-emergent herbicides stop the weed before it sprouts, offering the most effective long-term control. These products should be applied in the late summer or early fall, typically around late September, before spurweed seeds begin to germinate.
Common active ingredients for pre-emergent control include isoxaben or simazine, which create a chemical barrier in the soil to suppress emerging seedlings. Note that many standard pre-emergent products formulated for crabgrass may not be effective against this specific broadleaf weed. Always ensure the chosen product is labeled to control Soliva sessilis and follow instructions regarding watering to activate the chemical barrier.
Post-emergent herbicides eliminate the weed after it has germinated and is actively growing. The best time for application is during the late fall, winter, or very early spring (December through February), when the weed is young and most susceptible to treatment. Targeting the plant during this cool-season period ensures the herbicide is absorbed fully before flowering and burr production begins.
Effective post-emergent products are selective broadleaf herbicides containing a combination of active ingredients such as 2,4-D, dicamba, and mecoprop (MCPP). These three-way products control a wide spectrum of broadleaf weeds without harming the turfgrass when applied correctly. Treating the spurweed before the burrs develop is crucial, as the hard seed capsule protects the mature seeds from chemical penetration. If application is delayed until the burrs have formed, the herbicide may kill the plant, but the hazardous burrs will remain in the lawn, ready to re-infest the area the following season.