To weed or not to weed. Sometimes weeding is a big job, so how can you tell which plant is a weed?
Are the tall plants in this photo weeds that I should pull?

What about this plant with pretty purple flowers?

Are these two plants weeds?

You can’t always determine what kind of plant it is, but plant ID tools will help.
Websites & Apps
A good place to start, is the Wildflower Search website. You can narrow down the possibilities by clicking on a map with the general location you saw the plant. You can narrow it down more by inputting if it’s a tree, shrub, flower, grass, etc. Entering the color of the flower and the time of year you observed it narrows it down even more. This site goes into more detail with options including the growth pattern of leaves and the number of flower petals but most of the time, just selecting the options already mentioned helps determine what it is.

Here in Oregon, you can get a paid app for Oregon Wildflower identification. It has similar features to the Wildflower Search site. This app is great to have on your phone when you’re out in the field. Is there a plant ID app where you live? They are a great resource!

Books & Extension Units
Of course you can consult a wide selection of field guides. Use those that cover your geographic area. Here are a few I use. Yes, that copy of Sagebrush Country has spent a lot of time in the field. 😉 If you’re looking for a more recently published field guide, see Wildflowers of Oregon: A Field Guide to over 400 Wildflowers, Trees, and Shrubs of the Coast, Cascades, and High Desert.

Don’t forget to consult your local Cooperative Extension Unit. If you take in a cutting, they can help you identify the plant. At the Oregon State University Extension Service office closest to me, I can “Ask an Expert” by sending in a photograph of an unidentified plant. They’ll help you with plant ID. Cooperative Extension Units have a wealth of information for gardeners. The one here in Central Oregon has a great publication on water-wise gardening that I have referred to numerous times.

My Favorite Plant ID Tool!
I saved my favorite plant identification tool for last. Install the Google Lens app and take a picture with your phone. Open the picture and click on the icon and your screen will sparkle like it’s been sprinkled with pixie dust. Then it will magically show you pictures with names of possible plants. I have also used this app for identifying random antiques, but identifying plants is what I use it for the most. Does Google Lens work perfectly in identifying everything? No! Yesterday I took a picture of a lizard on a juniper tree. It told me it was a pangolin, a type of scaly anteater, on bamboo. 😀 However, Google Lens usually narrows things down and then you can refer to field guides, etc.
So back to my original questions about if I should pull the plants pictured.

Google Lens tells me the first plant is a type of mullein. They are considered a weed where I live. However, birds love the seeds on those tall stalks so I leave a few in the landscaping for them. It’s okay to keep plants that aren’t native if you keep them from getting out of control.

The second plant, with the pretty purple flowers, is spotted knapweed. It is so invasive around Central Oregon that you can be fined up to $750 a day per lot. I pull every one of those I see. The local Noxious Weed Program helps landowners identify aggressive, non-native plants.
The last picture is a twofer. Are these plants weeds? I can click on each plant and Google Lens will tell me what they are. The yellow flowered plant is Oregon sunshine. This native plant grows like a weed, but I love its cheerful color and long-lasting blooms so I don’t pull it. The pink flowered plant is iceplant. It’s an escapee from a landscaped part of our yard. It gets no water where it is but it’s doing great! Both these plants will stay where they are.
Good luck with your attempts at plant ID. Hope these tools help.
Friday Flowers
Wonderful information. Now I need to go outside and get to work.
Thanks, Ralph! Too hot out there right now.
Great info! I’m downloading a wildflower ID app for Idaho as I type and will try Google Lens. I’m a fan of bird ID apps, so I’m not sure why I haven’t already downloaded a wildflower app since I’m constantly taking photos of them. In addition to two wildflower ID books, I often consult this website to identify wildflowers here in Idaho: https://uswildflowers.com/. You can narrow it down by state, color of flower, etc. I don’t always find what I’m looking for there, so hopefully wildflower ID apps will fill the gaps. Thank you!
Glad you liked the info in my post! I’ll check out that site you mentioned. I use iBird Pro for birding. Apps can be really helpful for doing ID work. 😁
I took a one-day herb class years ago, only to discover that a lot of what I thought were weeds– were indeed beneficial herbs.
Art
That was good that you found that out! I learned a lot in a class I took on edible plants many years ago.