Where tumbleweeds come from, when to pull them so they never break loose, and what the County expects in Hesperia, Victorville and Apple Valley.
Get a Free Yard EstimateA tumbleweed is a mature Russian thistle plant that has dried out, snapped off at the base and started rolling, scattering seed as it goes. The way to stop them is to pull the plants while they are young and green in spring, or mow them when they start to bloom, before they seed. San Bernardino County requires tumbleweeds be completely removed from desert-region properties.
Russian thistle is not one plant. UC IPM groups several similar Salsola species under the name, including S. ryanii, S. kali and S. tragus (UC IPM). UC says it is common especially in the southern region up to 8,900 feet and grows best on loose sandy soils (UC IPM Weed Gallery). Graded lots and bare side yards in the Victor Valley are about as good as it gets for this weed.
This page is one part of our High Desert weeds guide.
Most people only notice it once it is a dry ball against the fence. It is much easier to deal with when you know the young plant.
| Stage | What UC IPM describes |
|---|---|
| Seedling | Stems often have reddish purple streaks. Seed leaves and first leaves are long and thin, like pine needles (UC IPM). |
| Mature plant | Bushy and round, about 3 feet tall (UC IPM), and from 18 inches to more than 6 feet wide. Leaves turn short, stiff and spine-tipped (UC IPM). |
| Flowering | July through October (UC IPM). |
| Tumbleweed | The dried plant breaks loose and the wind carries it, spreading seed for miles (UC IPM). |
UC IPM also notes the plant can cause skin rashes and pollen allergies (UC IPM). Wear gloves and long sleeves when you handle it, young or old.
UC IPM says germination normally happens in late winter or early spring, but it can keep going into summer and fall whenever there is moisture. Plants mature from July through October in California (UC IPM).
That gives you a clear window. From spring into early summer the plants are small, soft and easy to pull. By July they are flowering, and by fall they are drying into the balls that end up on your fence and your neighbor’s.
Seedlings with needle-like leaves. Pull them, roots and all. This is the cheapest time to win.
More seedlings after rain or irrigation. Keep pulling. Mow or cut any larger plants when they begin to bloom (UC IPM).
Plants dry out and break loose. If they have already seeded, UC says to collect the plants and dispose of them (UC IPM).
A large Russian thistle can produce more than 200,000 seeds. The good news is in the next line of UC’s pest note: over 90% of the seed either germinates or decays in the soil during the first year (UC IPM).
That is the opposite of goatheads, whose seed can wait five years. With Russian thistle, if you stop every plant on your lot from seeding for two or three years, the seed left in your soil drops off fast. What you cannot control is the neighbor’s lot upwind. Wind-blown plants will keep bringing new seed, so plan on a spring pull every year even after your own seed bank is gone.
For comparison, see our pages on goatheads and Sahara mustard, the other two weeds that fill High Desert lots.
Because Russian thistle germinates in late winter or early spring, the pre-emergent has to go down before that. For the Victor Valley floor, our estimate from NOAA temperature data is late February to mid-March. The math is on our rock and gravel weeds page. Water it in with about 1/2 inch of water, since UC IPM says pre-emergents need to be moved into the soil (UC IPM).
UC IPM lists flaming as an option for small Russian thistle seedlings (UC IPM). It also warns, in its landscape weed guide, to be careful not to flame dried out vegetation (UC IPM). A dry tumbleweed is exactly that.
Our advice, as general practice rather than a rule from any agency: skip the torch entirely once the weather warms up and plants start drying out, and never try to burn a pile of tumbleweeds. Pull, cut and haul instead.
UC IPM’s instruction is simple: collect the plants and dispose of them (UC IPM). It does not name a method, so here is general practice:
Do not leave a pile sitting against a fence or wall. That is the fire hazard the County is inspecting for.
The County’s desert-region standard is direct: “Tumbleweeds must be completely removed from your property” (SB County FHA). The rule does not carve out plants that blew in from somewhere else. If they are on your lot, they are yours to clear.
The County’s Fire Hazard Abatement program surveys the Valley and Desert regions twice a year, in early spring and early fall, and gives owners 30 days to fix a violation (SB County). In Hesperia, the City says fall inspections focus mainly on tumbleweeds and summer vegetation (City of Hesperia).
Rules differ by city. Victorville, Apple Valley and Adelanto each handle this their own way. Our High Desert weed abatement guide has the details and the official contacts.
A tumbleweed is a mature Russian thistle plant, one of several similar Salsola species, that has dried out and broken loose. The wind rolls it along and it drops seed as it goes. UC IPM says it grows best on loose sandy soil and is common in southern California up to 8,900 feet.
Pull them in spring and early summer while they are young, soft and easy to pull. UC IPM says Russian thistle flowers from July through October, so any plant you miss should be mowed or cut when it begins to bloom, before it sets seed.
In the desert region of San Bernardino County, the rule says tumbleweeds must be completely removed from your property. It does not make an exception for plants that blew in from another lot. The County surveys in early spring and early fall and gives 30 days to comply.
UC IPM says to collect the plants and dispose of them. Bag or bundle them on a calm day so seed does not scatter, and ask your trash hauler or city how they accept bulky yard waste. Do not burn them, since UC warns against flaming dried out vegetation.
UC IPM lists isoxaben, oryzalin, pendimethalin and trifluralin as pre-emergent options for Russian thistle. Apply before the late winter to early spring germination, water it in, and follow the product label, since many products are not labeled for every plant or site.
We checked every number on this page against the public sources below. If a rule or date changes, the agency page is the final word.
Russian thistle likes loose, bare, sandy ground. Monarch turns that ground into finished rock, DG and turf yards with fabric and a planned layout. We do not do weed spraying or lot clearing, but once it is clean we can build something that is easier to keep that way. Get a free estimate.
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