How to distinguish between the three types of weeds on your property
Isn’t it funny when you look at children that you have not seen in a while, you usually say, “These kids have grown like weeds.” You don’t say that they have grown like a plant. You and I did not make that saying up; the truth is weeds do grow fast!
But to someone clover is a weed, and to another person it is beneficial. Loving a weed can also be in the eye of the beholder. A weed is defined as a plant that is not valued where it is growing, and is usually a vigorous grower, especially one that tends to overgrow or choke out more desirable plants.
There are three types of weeds; native, non-native, and invasive, also known as noxious.
What are native weeds?
Native weeds are those that are native to their existing ecosystem. These native weeds are indigenous plants that have adapted, are highly aggressive, and often appear in disturbed sites or gardens. California Poppy, Eschsholzia californica, is our state flower and easily self-sows like a weed, but it provides early-season nectar for native bees, and its deep taproots help break up heavy or compacted soil.
What are non-native weeds?
Non-native weeds were brought from a different ecosystem by accident or intentionally, and they are not usually harmful to the environment, humans, or livestock. Non-native weeds that are beneficial include the Common Dandelion, Taraxacum officinale, which was introduced from Europe and differs from the native California Dandelion, Taraxacum californicum which resides in the San Bernardino Mountains. The Common Dandelion has a vibrant yellow blossom and might seem like a garden invader, but it’s a nutritional superhero. Every part of a dandelion can be eaten, and it has vitamins A, C, and K. The leaves make a fantastic addition to salads, offering a slightly bitter, earthy flavor. Plus, the roots can be roasted for a healthy coffee substitute.
Identify and eliminate invasive weeds
Invasive weed species are a subset of non-native species that cause harm to the environment, economy, or human health. They compete with native species for resources, disrupt ecosystems, and lead to ecological imbalances. The introduction of invasive species often results in negative impacts on local biodiversity.
One invasive weed is the Yellow Star Thistle, Centaurea solstitialis originally from the Mediterranean region; highly aggressive, it degrades and contaminates crops and grazing land, and is toxic to horses. Another noxious weed is the Stinkwort, Dittrichia graveolens. which is also from the Mediterranean, Southern Europe, and Northern Africa. It has only been in California since 1984, and since then, has spread throughout the state. Its ability to adapt to overgrazed pastures and roadsides means it takes over for native plants which local insects and animals depend on.
Before you head off to battle the weeds, it is advantageous to know the type of weed you are going after because it may be a friend and not a foe.
UC Master Gardeners of El Dorado County are here to help you identify the weeds on your property! Take a picture and complete our Ask a Master Gardener survey! Or take a clipping, seal it up tight in a plastic baggie, and bring it in to our Placerville office during our office hours.
This article by UC Master Gardener of El Dorado County Diane Lehr originally appeared in the Mountain Democrat in June 2026.