UCCE Master Gardeners Plumas-Sierra
University of California
UCCE Master Gardeners Plumas-Sierra

What's that Weed?

Properly identifying that pesky weed in your lawn or garden is the first step to effective management.

The tools below walk you through the process of properly identifying common garden weeds.

UC IPM Identification Key to Weeds

UC Weed Research and Identification Center ID Tool

Other resources:

Weed Management in Landscapes

Weed Management in Lawns

Invasive Plants

Common Weeds in Plumas & Sierra Counties

Noxious Weeds

Noxious weeds are plants that cause harm to agricultural lands, natural habitats and ecosystems. Most noxious weeds have been introduced into an ecosystem and, therefore, often lack the predators that would normally limit their growth. This allows aggressive species who can tolerate a broad range of habitats and compete well for resources to proliferate and take over new ecosystems.

Below is a list of noxious weeds found in Plumas & Sierra Counties. If you find these weeds in your garden or landscape, please follow the suggested guidelines for removal. If you need help with weed identification please contact us. For questions about controlling large patches of noxious weeds, contact the Plumas-Sierra Agricultural Commissioner.

bull thistle

Bull Thistle

canadian thistle

Canadian Thistle

Dalmation Toadflax2

Dalmation Toadflax

hoary cress

Hoary Cress

spotted knapweed

Knapweed (Spotted & Diffuse)

russian knapweed

Knapweed, Russian

leafy spurge

Leafy Spurge

medusa head


musk thistle

Musk Thistle

tall whitetop

Perennial Pepperweed (Tall Whitetop)



rush skeletonweed

Rush Skeletonweed

Scotch Thistle

sulfur cinquefoil

Sulfur Cinquefoil

star thistle

Yellow Starthistle


Garden Weeds

While they may not cause the same kind of ecological damage as the weeds listed above, dealing with garden weeds can be frustrating and time consuming as well. Follow the management tips listed below for safe and effective weed management.


Field Bindweed


Miner's Lettuce

Mallow (Cheeseweed)


Poison Oak




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