Foxtails are grassy weeds that pose a significant health risk to pets and livestock. The danger lies in the plant’s mature seed heads, which are covered in sharp barbs known as awns. These barbed seeds are designed to burrow into the soil, but they readily attach to animal fur. Once attached, the awns can only move forward, migrating deep into soft tissues, including nasal passages, ears, eyes, and between paw pads. This migration causes severe inflammation, infection, and abscesses, potentially leading to serious health complications if the seed migrates into internal organs.
Physical and Mechanical Removal
For small infestations or in areas where chemical use is not desired, physical removal is the most direct solution, provided it is executed before the seeds mature. Manually pulling foxtails is highly effective but requires removing the entire fibrous root system to prevent regrowth. The best time for this is early in the season when the plants are young and the soil is moist, making the roots easier to extract completely.
Any plants with developing seed heads must be carefully bagged and removed from the property, as the seeds can continue to mature and drop even after the plant is pulled. Mowing is only beneficial if timed precisely before the seed heads begin to form. Once the distinctive bushy spikes appear, mowing should be avoided because it will shatter and spread the barbed seeds across a wider area.
If mowing is used, the deck height must be set high enough to stress the foxtail while encouraging the growth of desirable turfgrass. Once seed heads are present, foxtails can produce new, shorter seed heads below the cutting height, rendering the effort ineffective.
For non-turf areas that are heavily infested, soil solarization is a viable non-chemical option. This process involves covering the cleared area with clear plastic sheeting for four to eight weeks during the hottest part of the year.
The clear plastic traps solar heat, raising the soil temperature high enough to kill existing weeds and the foxtail seed bank. Soil should be watered thoroughly before application to increase heat transfer, and the edges of the plastic must be securely buried to maintain the necessary high temperature.
Applying Targeted Herbicides
Chemical control requires a two-part strategy: addressing seeds in the ground and eliminating emerged plants. The first line of defense is a pre-emergent herbicide, which creates a chemical barrier in the soil that prevents seeds from sprouting. Effective pre-emergent active ingredients include Prodiamine, Pendimethalin, and Dithiopyr.
Timing is paramount; pre-emergent must be applied in the spring before soil temperatures consistently reach 65 degrees Fahrenheit. Applying these products too late reduces effectiveness, as the goal is to stop development before the seed breaches the soil surface.
If the timing window is missed, post-emergent herbicides are necessary to eliminate established plants. Since foxtail is a grass, common broadleaf herbicides will not work, requiring a selective product designed for grassy weeds if preserving the lawn is a concern. Selective options, such as Quinclorac and Fenoxaprop-p-ethyl, target the foxtail while being tolerated by established turfgrass.
A non-selective herbicide, such as Glyphosate, provides the most complete kill but eliminates any other vegetation it contacts. This makes it suitable only for driveways, fence lines, gravel areas, or preparing a heavily infested area for re-seeding. Always follow the label instructions exactly, use protective equipment, and avoid application on windy days to prevent drift.
Preventing Future Infestations
Long-term control relies on cultural practices that make the environment inhospitable for foxtail seeds to germinate and thrive. Foxtails establish easily in thin turf, bare soil, and disturbed areas. Maintaining a dense, healthy lawn is the most effective preventative measure, as a thick canopy physically blocks the sunlight necessary for foxtail seeds to sprout.
Density is achieved through proper fertilization and mowing at the highest recommended height. This encourages deeper root growth and helps the lawn shade the soil surface, further suppressing weed seed germination. Deep, infrequent watering also favors established turf over shallow-rooted weeds, keeping the soil surface drier to discourage foxtail germination.
Improving soil health through aeration helps reduce compaction, which foxtails tolerate well but stresses desirable turfgrass. In garden beds, a thick layer of organic mulch (three to four inches deep) blocks sunlight and prevents germination. Addressing bare patches by overseeding immediately removes the open invitation for foxtail to establish itself.