Hordeum murinum, Bromus madritensis ssp. rubens, Bromus diandrus
A Grass With Many Names — and One Purpose
“Foxtail” is not a single plant. It is a common name applied to several invasive annual grasses, all introduced from Mediterranean Europe, all thriving in disturbed soil, and all sharing the same survival strategy: a seed head armed with barbed bristles engineered to attach to anything that moves and never lets go.
The species most common in the Santa Cruz Mountains are hare barley (Hordeum murinum), foxtail brome (Bromus madritensis ssp. rubens), and ripgut brome (Bromus diandrus) — the last named for its capacity to pierce the stomach lining of grazing animals.
All three are listed by the California Invasive Plant Council, and all three follow the same life cycle:
- Germinating with the first fall rains
- Growing steadily through winter and spring
- Setting seed by late spring
- Dying by summer — leaving behind hundreds of barbed seeds per plant, each one designed to travel
Understanding this life cycle is where effective control begins.
The Seed That Does Not Let Go
Each foxtail seed head is built around a single purpose. The barbed bristles point backward from the seed tip — a design that allows movement in only one direction: forward.
Fur. Feathers. Skin. Clothing. Once attached, it does not release. It burrows.
A single foxtail plant produces hundreds of seeds. Those seeds attach to every hiker, bobcat, mountain lion, and deer that moves through an infested area — to be carried across the landscape to soil that may be miles from the parent plant.
Seeds that reach the ground persist for one to two years — meaning a patch cleared this season can re-emerge from seeds already waiting in the soil.
Foxtail's preference for disturbed ground makes every bare patch, path edge, and hillside vulnerable to establishment. Once established, it displaces the native annual forbs — such as lupine and evening primrose — and perennial bunchgrasses that would otherwise hold that ground.
It Is Not Just a Dog Problem
Every San Lorenzo Valley resident who has walked a dog through summer grass knows what foxtail does. The seeds embed in paws, ears, nostrils, and eyes — working through skin and tissue, causing infections and abscesses that send animals across the valley to veterinarians every season.
Foxtail is one of the few invasive plants people here already understand — because they’ve experienced it.
The more foxtail we remove from roadsides, public lands, and our own gardens, the safer the valley becomes for the animals who live alongside us.
But what we see in our pets is only part of the story.
Foxtail in the Food Chain
Foxtail does not distinguish between a dog and a hiker, a deer, or a hawk.
Its seeds are built to move in one direction—forward. Once embedded, they continue working into tissue, where they can cause infection, blindness, and sometimes death. These impacts are well documented in veterinary medicine and have also been observed in birds.
In one long-term California study, 18 of 124 hawks examined had one or more foxtail awns embedded in or around their eyes—foxtail brome, ripgut brome, and foxtail barley—which caused corneal damage, infection, and, in some cases, blindness.
These birds were hunting in grasslands, creek margins, and forest edges where invasive grasses have become dominant.
Small mammals—the mice, voles, and shrews that form the base of the food web—are equally vulnerable. Seeds work into ears, nostrils, and skin, moving through tissue and causing infections that can be fatal.
Ground-foraging birds move through the same landscapes, where foxtail increasingly replaces native ground cover. Over time, these shifts don’t just injure individual animals—they change which species can safely live and feed there at all.
The Forest Begins at Your Driveway
The San Lorenzo Valley is not suburban. It is a community embedded in a living forest, where the line between a garden and a wildland is not a fence but a gradual transition — forest into garden, wildland into yard — without a sharp boundary between them. Every driveway edge, every un-mulched slope, every neglected path margin is either part of the problem or part of the solution.
Removal Timed to the Life Cycle
Foxtail is a winter annual. That life cycle is its greatest vulnerability — and the foundation of every organic removal strategy.
Before seed heads form:
- Pull early, before seed set, while the soil is moist from winter rains and roots are shallow enough to lift cleanly. A firm grip at the base and a straight upward pull removes the entire plant.
- Work backward across the area, keeping your weight off freshly cleared soil to protect the organisms and dormant native seeds waiting beneath the surface.
- Foxtail can also be weed-whipped at this stage and left on the ground — the cut material poses no dispersal risk and adds organic matter to the soil.
Once seed heads begin to emerge:
- Pull by hand, bag the whole plant, roots and all, and dispose of it in the green waste bin. Weed whipping at this stage disperses seeds more widely than hand removal and should be avoided when possible.
- If the soil has hardened and the plant will not pull cleanly, cut the stem below the seed head and bag the seed head immediately — partially developed seed heads continue to ripen after cutting and can produce viable seeds even after removal. The remaining stems and roots will not regenerate and can be left standing, or weed whipped and left on the ground as mulch.
- Do not compost foxtail at any seed stage.
Seeds persist in soil for one to two years. Return to cleared areas each season — the seed bank depletes over two to three years of consistent removal, but only if foxtail is not allowed to reseed. A single season of inattention restocks it entirely.
When the Window Has Passed — and How to Plan Ahead
By mid-spring, foxtail across a large area is already in seed. Weed-whipping at this stage is a reasonable and necessary response to fire fuel.
But it is worth understanding what is happening: seeds are being scattered across the ground at the moment they are most viable, restocking the seed bank for the next year’s season.
This is not a reason to stop. It is a reason to plan ahead.
You know where that patch is. In January or February, when the plants are tall enough to cut efficiently, and the seeds have not yet formed, weed whip the entire area. The cut material remains on the ground as mulch, with no risk of dispersal. No bagging. No hand pulling.
Weed whipping handles this year's fuel. Early weed whipping before seed set is how you reduce next year's infestation — and the one after that.
Close the Ground — Keep It Closed
Every patch of bare soil is an opportunity foxtail will not miss. The solution is native plants, native shrubs, and mulch — conditions that deny foxtail the bare ground it depends on.
Where no native seed bank is assumed to be present, apply mulch or chips to cleared, bare areas as soon as possible — three to four inches deep — to suppress foxtail germination and protect the soil while native plants are reintroduced.
Where a native seed bank may be present, a deep chipping will suppress it along with the foxtail. Apply lightly or leave the soil undisturbed and allow natives to reemerge on their own. Monitor seasonally for the reemergence of foxtail and remove by hand before seed set.
Native perennial grasses, groundcovers, and forbs establish deep root systems that hold soil and close the canopy at ground level, creating the stable, living surface that foxtail cannot as easily colonize.
The native plants that belong in the San Lorenzo Valley belong here for a reason — they evolved alongside the insects, birds, and soil life that depend on them. Many are already present, dormant in the seed bank or suppressed beneath the infestation, waiting for the light and space that removal of the foxtail creates.
The goal is not one garden cleared or one season of removal. It is the eradication of foxtail from the San Lorenzo Valley — replaced by a landscape dense with native plants, from the driveway edge to the forest margin, one cleared patch at a time, one planted native at a time, until the ground closes and holds.
From the Airwaves: Foxtails
Listen in as NHRP Director Linda Skeff joins Sunday Morning Live! on KBCZ 89.3 FM to talk about foxtails—what they are, why they spread, and what we can do about them locally.
The San Lorenzo Valley Native Habitat Restoration Program integrates environmental and community needs to restore the riparian habitat and ensure the ongoing health and beauty of the watershed.
From the Airwaves
Listen to radio interviews with Linda Skeff on KBCZ.
