Foxtails are a pervasive group of grassy weeds that threaten both manicured landscapes and the health of pets and livestock. These annual grasses, which include species like yellow, green, and giant foxtail, are known for their resilience and ability to spread rapidly through seed dispersal. Tackling a foxtail infestation requires a methodical approach that combines immediate removal techniques with long-term preventative measures. Understanding their life cycle and vulnerabilities is the first step toward effective control.
Identifying the Weed and Its Dangers
Foxtail grasses are distinguishable by their grass-like foliage and characteristic seed heads that emerge in the summer months. The mature seed head is a dense, spiky cluster resembling a fox’s bushy tail, typically ranging from a few inches to nearly a foot in length. These seed heads transition from green to a hardened, yellow or brown as they mature and dry out, signaling their most dangerous stage.
The danger lies in the seeds, which feature sharp, backward-pointing barbs, also known as awns. These barbs allow the seeds to cling easily to fur and clothing, and they migrate only deeper into tissue. Once embedded, the seeds can cause serious complications because the organic material does not break down inside the body.
Pets are particularly susceptible, as the barbed seeds can burrow into the nasal passages, ears, eyes, and between the toes of a dog’s paws. Symptoms like excessive sneezing, head shaking, pawing at the face, or a persistent limp can indicate an embedded foxtail. Internal migration can lead to abscesses, severe infection, or travel to vital organs, necessitating immediate veterinary intervention.
Manual and Mechanical Eradication
For small, isolated patches, manual removal is the most immediate and effective non-chemical solution for foxtail control. Hand-pulling the plants before the seed heads fully develop is crucial to prevent the dispersal of the barbed seeds. When pulling, remove the entire root system, as this is an annual plant.
Mowing can be a useful tool, but timing is important. Regular mowing that keeps the plant short can prevent the formation of seed heads entirely. However, if the seed heads have already formed, mowing can scatter viable, dangerous seeds across a wider area. Mowing established weeds often proves ineffective for eliminating the seed threat.
For large, dense patches of foxtails, especially in non-turf areas, solarization or smothering can be employed. This involves cutting the weeds low and covering the area with clear or black plastic sheeting for several weeks during the hottest part of the year. The heat trapped beneath the plastic will effectively kill the plants and the seeds near the soil surface.
Proper disposal of all pulled or cut foxtail material is necessary to prevent re-infestation. Because the seeds can remain viable for several years, any plant material with mature seed heads should be bagged and disposed of as trash rather than placed in a compost pile.
Using Herbicides for Control
Chemical control of foxtails relies on differentiating between pre-emergent and post-emergent applications, which target the weed at different stages of its life cycle.
Pre-Emergent Herbicides
Pre-emergent herbicides interrupt the germination process before the plant sprouts. These products should be applied in the early spring, typically when soil temperatures rise above 68 degrees Fahrenheit, to form a chemical barrier in the soil. Common active ingredients include prodiamine, pendimethalin, and dithiopyr. Applying the herbicide too late, after germination, renders the treatment ineffective. A subsequent application in late summer or fall may be necessary to control a second wave of germination.
Post-Emergent Herbicides
Post-emergent herbicides treat plants actively growing above the soil line. For foxtail growing in a lawn, a selective post-emergent herbicide is necessary to kill the weed without harming the desirable turfgrass. Products containing fenoxaprop-p-ethyl, quinclorac, or topramezone are recommended for selective control in turf. If foxtails are growing in cracks, driveways, or areas where no other vegetation needs to be preserved, a non-selective post-emergent herbicide, such as one containing glyphosate, can be used. These treatments kill all plant life they contact. Always follow the product label for application rates and safety precautions.
Preventing Future Infestations
Long-term foxtail control shifts the focus from elimination to creating an environment where the weed cannot thrive. Foxtails are opportunistic annual weeds that flourish in disturbed, bare, or compacted soil, often outcompeting stressed turf. Improving the overall health and density of the desired lawn or landscape plants is the most durable preventative measure.
This involves ensuring the soil has the correct nutrient balance, determined through soil testing, and adjusting fertilization practices accordingly. Adequate watering encourages deep root growth in turfgrass, rather than shallow watering that favors weed germination.
Overseeding an existing lawn with desirable, competitive grass species is an effective technique to crowd out available space for foxtail seeds to germinate. A dense stand of turf blocks sunlight from reaching the soil surface and competes for water and nutrients, which naturally suppresses weed growth.
Applying a thick layer of organic mulch in garden beds and non-turf areas can also prevent foxtail seeds from receiving the light necessary for germination. Minimizing soil disturbance from tilling or excessive foot traffic will reduce the opportunities for foxtail seeds to take hold in freshly exposed ground.