Burrow weed, also known as lawn burweed ( Soliva sessilis ), is a common annual broadleaf weed that can become a nuisance in lawns and cultivated areas. It is particularly recognized for its distinctive, prickly burrs that cause problems when mature.
Identifying Burrow Weed
Burrow weed is an annual plant with a prostrate, low-growing habit, spreading outwards from a central base. Its bright green leaves are finely divided or lobed, resembling parsley, and are arranged oppositely along the stems. The plant produces very small, inconspicuous green flowers clustered in the leaf axils.
The most distinguishing feature of burrow weed is its burrs, which develop from these flowers. These small, flat burrs are armed with sharp spines, making them painful if stepped on. They are the primary means of seed dispersal and help differentiate the plant from other low-growing weeds.
Understanding the Impact of Burrow Weed
Burrow weed poses challenges due to its spiny burrs. These burrs readily cling to clothing, shoes, and the fur of pets and livestock, causing discomfort for people walking barefoot and leading to matted fur or skin irritation in animals. The sharp spines can also cause foot irritation in livestock.
Beyond physical discomfort, burrow weed impacts the health and aesthetics of lawns and agricultural lands. It competes with desirable turfgrass for essential resources like nutrients, sunlight, and water, leading to thinning and weakening of the lawn. In pastures, its presence can reduce forage quality and impact animal productivity, as animals may avoid grazing in infested areas.
Effective Control and Removal Methods
Controlling existing burrow weed infestations involves several practical approaches, depending on the scale and maturity of the weeds. For small patches or individual plants, manual removal is effective, especially before the burrs mature and set seed. Hand-pulling is most successful when the soil is moist, allowing for the removal of the entire root system to prevent regrowth. Wearing protective gloves is advisable due to the plant’s spiny nature.
Mechanical control methods can also be employed. Mowing can help reduce the plant’s ability to produce seeds, but it is important to use a mower with a catcher to collect any dislodged burrs and prevent further spread. However, mowing alone may not fully prevent seed production, as the plant can adapt to lower heights. For larger areas, hoeing or shallow tillage can disrupt the weed’s growth, particularly in dry conditions where uprooted plants will desiccate.
Chemical control offers another option, with both pre-emergent and post-emergent herbicides available. Pre-emergent herbicides are applied before the weed seeds germinate, typically in late autumn or early winter, to create a barrier that prevents seedlings from establishing. Products containing ingredients like prodiamine or pendimethalin are often recommended for preventing burrow weed.
Post-emergent herbicides are used on actively growing plants and are most effective when applied in early winter before the burrs have fully formed. Herbicides containing active ingredients such as MCPA and dicamba are commonly used for broadleaf weed control in turfgrass. Always read and follow product label instructions carefully for safe and effective application.
Preventing Future Infestations
Preventing burrow weed from returning requires a multi-faceted approach focused on long-term lawn and garden health. Establishing a dense, healthy turf is a primary defense, as thick grass competes effectively with weeds for light, water, and nutrients, leaving less space for burrow weed to establish. Proper cultural practices, such as maintaining appropriate mowing heights, ensuring adequate watering, and regular fertilization, contribute significantly to turf density and vigor.
Improving soil health also plays a role in prevention. Burrow weed tends to thrive in compacted soils, so aeration can help create a less favorable environment for its growth. Over-seeding bare or thin areas of the lawn promptly can also prevent weed seeds from germinating in exposed soil. Additionally, diligent seed control is important; cleaning gardening tools, shoes, and pet fur after being in infested areas can prevent accidental spread of burrs and seeds to new locations. Regularly monitoring your property for any new or emerging burrow weed plants allows for early intervention before they can produce more seeds and spread.