Invasive Weeds

Friends of Tahoe Donner Trails has been working with the Weed Warriors from the Truckee River Watershed Council since 2013 to increase awareness of non-native invasive weeds here in Tahoe Donner. Because this topic has proven so popular, the trails club has adopted the goal of recruiting and training a network of volunteer weed spotters to monitor the association’s 7,000 acres for invasive weeds on a consistent and long-term basis.

Invasive weed spotting is a rewarding activity for all ages, and a great way to protect the integrity of our local natural environment. You can be a weed spotter every day in your yard, your neighborhood, and on the trails. And because it’s almost like a natural scavenger hunt, weed spotting is also quite fun. If you catch the weed spotting bug, you might even find it a little addictive.

Frequently Asked Questions

Q. What are invasive weeds? How do they differ from noxious weeds?

A. Non-native invasive weeds are introduced, alien plant species that adapt so readily and reproduce so rapidly that they disrupt, out-compete and displace native plants. Some non-native invasive weeds have proven so damaging that they are legally classified as “noxious weeds,” and are subject to legal regulation and quarantine by state and county governments.

Q. I think I found an invasive weed. What should I do?

A. If you are uncertain about the species, you may email a photograph of the plant to the Trails Club to confirm identification. Photographs of flowers (especially in profile, so we can see both the flower and the bracts below it), and photographs of leaves are especially useful. In your email please detail the location of your sighting, and include GPS coordinates or an address if possible. If identification is difficult, we may visit the site to take a closer look. Information about the size of the infestation is also useful. The next step will depend on the specific species of invasive weed identified. In some cases they must be reported to county agencies for professional treatment. The Trails Club can assist you with that process. Also, see below on the difference between reportable and non-reportable weeds.

Q. Which invasive weeds are here in Tahoe Donner?

A. The Trails Club maintains a catalog and map of all known current and historical invasive weed infestations in Tahoe Donner. Within the last year bull, musk, and Scotch thistle have all been found here. So have diffuse, Russian, and spotted knapweed. Perennial pepperweed, poison hemlock, oxeye daisy, and cheatgrass are here as well. In truth, however, we do not fully know what is growing in Tahoe Donner, because we do not have a sufficient number of volunteer weed spotters to cover the association’s considerable acreage. Bull thistle and spotted knapweed are perhaps our most widespread invasive weeds, but the absolute worst invasive weeds in Tahoe Donner are those we have not yet discovered.

Q. Where are invasive weeds growing in Tahoe Donner? How did they get here?

A. Invasive weeds are growing everywhere in Tahoe Donner. They are in common areas, outside amenities, along the trails, on roadsides, and on private lots. They arrived here the same way they arrived everywhere beyond their native range: in ignorance or by accident, human beings transported them.

Q. Who should become a weed spotter?

A. Everyone should become a weed spotter. Golfer or gardener, hiker or biker, runner or walker, eight or eighty, full-time or part-time, weed spotting is truly for everyone. Even if you simply like to sit outside and enjoy your yard, you should know how to spot a noxious weed invader. If everyone who walks their dog in Tahoe Donner became a weed spotter, we’d have every inch of this place covered.

Q. I’d like to become a weed spotter. How can I learn more about invasive weed identification in this area?

A. The first thing you should do is email the Trails Club and tell them of your interest. Weed spotting is all about developing the habit of noticing things that most people overlook, and the Trails Club can help you acquire the training and information you need to develop that habit. We keep our members well informed of all invasive weed workshops and events, both within Tahoe Donner and throughout the region. And, of course, we sponsor some of those workshops and events right here in Tahoe Donner.

Although the absolute best way to learn about invasive weeds is to see them out in the field, there are also a number of booklets, pamphlets and online resources available. In particular we recommend:

Q.  Does Tahoe Donner’s management have a role in controlling invasive weeds within the association? If they do, why do we need volunteer weed spotters?

A. Tahoe Donner is authorized by the C&Rs to manage invasive weeds across the entire association, and has consistently expressed both awareness and concern about the problem. While the Association has been open to discussions about taking a more active role managing invasive weeds, for the moment no portion of Tahoe Donner’s land management team is fully tasked with that responsibility, either on association land, public roadsides, or private lots. Nor would it be practical for them to assume that responsibility in full. We will always need a corp of trained volunteer weed spotters here in Tahoe Donner.

Q. Why are some weeds reportable, and others non-reportable? What is the difference between Class A, B, and C noxious weeds? 

A. Fighting invasive weeds is no different than anything else: resources are limited, and you have to set priorities. The state of California helps to set these priorities by rating invasive weeds according to the severity of their threat, the likelihood of their eradication or containment, and their distribution across the state.

In this state noxious weeds are categorized either as class A, B, or C. Class A and B weeds are the reportable classes of weeds, with Class A weeds having a higher priority than Class B weeds. From a public policy point of view, it makes good sense to focus limited resources on these weed classes. Reportable weeds  should be brought to the attention of county agricultural commissioners.

Class C weeds are not necessarily any less of an objective threat than Class A weeds. A weed may be classified as Class C simply because it has grown so widespread that its eradication or containment is now economically impossible.

These class designations are, however, only guidelines, and sometimes local considerations override them. For instance, here in the Lake Tahoe Basin Yellow Star Thistle is treated as if it were a Class A weed even though the state categorizes it as a Class C weed.