Tumbleweeds, Maui Fires, and Fairfax County: Could it Happen Here?

This photo was taken along Park Road, Franklin Park in McLean, by a passerby on a damp morning in April 2022. The cause of this fire is unknown. It was quickly addressed.

Consider these three iconic symbols of the Old West: tumbleweed, Mustangs, and John Wayne. All are imports to this country! John Wayne was of Scotch-Irish descent; Mustangs are descended from horses brought here by the Spanish, and tumbleweed was imported from Russia in contaminated flax seed. All these Western symbols are still with us in one way or another. Today only one, tumbleweed, has done enormous damage, practically overrunning the landscape of the American West. 

Seen in old Westerns rolling through ghost towns and across open plains, tumbleweed is also known as Russian thistle (Salsola tragus). As the story goes, Russian immigrants carried its seeds into South Dakota in 1873. Once it took root on American soil, its reproduction was wildly successful—to the point of pestilence.

Russian thistle is a large, bushy plant with reddish-purple stems and delicate flowers. When the live plant dies, it leaves a desiccated skeleton that breaks away from the root. This is what becomes tumbleweed, traveling wherever the wind takes it and dispersing its 250,000 seeds per plant. With this very effective method of seed dispersal, Russian thistle became a major problem for farmers in just 20 years. So much so that in 1894 the USDA published a document entitled , “The Russian Thistle: Its History as a Weed in the United States, with an Account of the Means Available for its Eradication”.

Well…eradication was not achieved in 1894. Today tumbleweed is so ubiquitous in certain areas that it has caused traffic problems by blocking roadways (attack of tumbleweed) and buried residents in their houses (trapped). While these problems could be little more than fodder for an interesting news article, a humorous annoyance, or a cause of severe frustration, tumbleweed poses serious threats. One threat is still its impact on agriculture. Another is that it is a fire hazard.  The devastating fires we have recently seen in western states have, in part, had invasive species such as tumbleweed as fuel contributors.

In the Maui fires, non-native, invasive species are also partly to blame for the speed of the fires’ spread and the massive devastation they caused. These invasive species were grasses, all brought to the islands intentionally in the 1800s for cattle forage. 

As in most any disaster, several factors were at play, including climate change and human error. But the contribution of invasive grasses cannot be minimized. These grasses out compete native plants, taking hold on unmaintained land, such as Hawaii’s abandoned sugar cane and pineapple fields that saw a decline in the 1990s.  It’s estimated that one-quarter of the land mass in Hawaii is dominated by invasive grasses. These grasses can grow nearly anywhere, are drought resistant, and die back without decomposing. This last characteristic means that they are flammable tinder awaiting an ignition source.

Sadly, a 2021 report on fire prevention put out by Maui County recognized the growing threat of fires due to higher temperatures, prolonged droughts, and invasive grasses. The report recommended an “aggressive plan to replace the hazardous fuel sources with native plants to reduce combustible fuel while increasing water retention.“ (msn: Hawaii tinderbox)

But could it happen here? Can we comfort ourselves that the East Coast is generally a humid environment; invasive grasses have not been imported to feed cattle; we have higher trust in our utility’s emergency response capability, infrastructure, and access to emergency services?

“There is no such thing as a fireproof plant”, according to Michele Steinberg of the National Fire Protection Association. Given the right conditions, all vegetation could combust, including native species. Plants that have a higher possibility of becoming an ignition source are those that produce resins and aromatic oils. Think: pines, fine-needled evergreen shrubs, and woody herbs such as rosemary.

The reason invasive plants can pose a higher risk is that they have a competitive advantage. They have no or very few natural predators, are prolific reproducers, and crowd out native plants. Common invasive species in Northern Virginia that fall into the flammable category are bamboo, Japanese honeysuckle (abcnews), and Japanese stiltgrass (BR PRISM Fact sheet).

As for honeysuckle, nine species grow in Virginia; and six are invasive, with Japanese honeysuckle one of the most notorious spreaders. Stiltgrass can be seen throughout Fairfax County, sometimes in very large patches of unmaintained lawn or roadway. It is a serious problem in many local and national parks. Running bamboo is prolific in our area. Due to its impact on the environment, Fairfax County implemented an ordinance requiring property owners to contain it or face possible fines (FC Bamboo). Perhaps the specter of flammability will add another reason for homeowners to speed its containment, if not eradication.

Despite the potential concern of a flammability hazard, all invasive plants are a threat to our ecosystem by tilting the balance of nature away from the insects, pollinators, birds, and other fauna that are and have been established members of our environment for eons. This, alone, is reason enough to control invasive plants; but it is harder to see the impact; and, therefore, harder to appreciate.

Japanese knotweed growing in 2022 along Vermont Avenue in Franklin Park. Control measures have been taken in 2023 to try and eliminate this invasive from this area. It will take several years to do so. Look for it along Old Dominion Drive. At this time of year, its flowers can help in identification.

There is also the concept of ‘green blindness’ where we believe anything green is good. But that is not always the case. Just a short drive around Fairfax County, invasive plants can be seen crowding out or blanketing native plants along most roadways. Japanese knotweed, for instance, is a woody shrub that is considered the one of the world’s most highly invasive plants and lines many streets throughout the county. It can be identified at this time of year by its delicate white or pale green clusters of flowers that sprout from its nodes. Porcelain berry, an imported ornamental vine, creates topiary trees in the summer. With the winter months, its leaves die back to reveal woody vines draping from the branches of nearly anything it can climb onto, including our stately deciduous trees. Chinese wisteria wraps itself around tree trunks, strangling the trees and eventually overgrowing the crown, blocking sunlight.

While these invasive plants might not be rated as flammable or combustible, the invasive vines will eventually kill the trees. And dead trees pose multiple safety problems from downed wires to traffic hazards to personal property damage to…yes… a fire hazard. Not to mention the wisdom of allowing utility wires to be encased by vegetation.

Porcelain berry vines in winter at Lewinsville Park, McLean. In general, trees that appear veiny or furry are likely being taken over and killed by invasive vines.

The problem of invasive plants is real, it is another threat to a balanced ecosystem, and it is overwhelming. The question then becomes, how is this problem going to be addressed and how does it get solved? The problem proliferates in unmaintained landscapes, such as along roadways and “natural” park lands. We will never adequately address the problem while garden centers continue to profit from the sale of invasive plants and unsuspecting homeowners unknowingly plant them (see: just say no-home depot). As the problem of invasive plants continues with little regulation or control, it is almost certain to become a burden to taxpayers.

In Fairfax County, the park authority has established an invasive management program, but funding is minimal, and work is conducted primarily through a volunteer system. The Virginia Department of Transportation budget does not include removal of invasives along roadways. Most utilities seem oblivious, given the proliferation of vines on utility wires.

In 2018, after fires in West Maui destroyed several homes, University of Hawaii plant ecologist and prominent fire expert, Clay Trauernicht, asserted that there is a need to “reimagine our individual and collective responsibility for the larger landscape.” (msn: fires) His statement eerily echoes the sentiment of the 1894 USDA report on Russian thistle, which opened by placing the onus of effective control “on the industry and perseverance of the farmers”.  For 150 years, then, the control of invasive species has been laid at the feet of citizens.

Given this may be the reality, the only question is: are we up to the task?

HELP LOCAL ORGANIZATIONS CLEAR INVASIVE PLANTS:

Chesterbrook Swim and Tennis Club/UFA- Mondays 9 am to 11 am (contact sweeneyfam@me.com)

Urban Forest Alliance (UFA) - Vermont Avenue, Franklin Park; Autumn dates TBA; see: Entrance Restoration

McLean Trees Foundation - contact Carol Wolter at info@mcleantreesfoundation.org or mcleantreesfoundation.org

Earth Sangha - invasive removal (or other) volunteer opportunities: Earth Sangha volunteer

Fairfax County Invasive Management Area Program - sign up for various locations through the IMA Program Calendar