what weed is it? putting names to pesky plants

garlic-mustardI KNOW A LOT OF PLANTS BY THEIR PROPER NAMES, but when it comes to “weeds,” as we term unwanted garden visitors that seem to just come with the territory, my knowledge really pales. So lately, on days not conducive to outdoor work, I’ve been studying up a bit from some great weed-identification websites, so that I can finally address Alliaria petiolata (garlic mustard, above) with the proper (dis)respect.

I didn’t even remember the botanical Latin name for the ubiquitous dandelion, Taraxacum officinale, below, until I became a regular on the Rutgers New Jersey Agricultural Experiment Station “weed gallery” recently. What I love about the Rutgers weed tool, besides its general appropriateness for my garden regionally speaking, is that I can browse by common names or by thumbnail photos (or by Latin names if I ever know one).

dandelion 3
The University of Minnesota’s “Is This Plant a Weed?” tool is another place you’ll find me, narrowing the field of possibilities until I get an ID by clicking through a series of photo-based prompts (such as grass or broadleaf….upright or creeping…and so on). It almost makes weeds fun. (Note the almost.)

Steve Brill, the so-called “Wildman” forager who teaches in Central Park in New York City and elsewhere, has a chart and plant profiles of edible weeds on his website, if you’re hungry, though you’ll have to scroll a third of the way down the homepage and click on “wild plants” (fourth blue box from the top) to get there. Once you do, you can serve up Japanese knotweed, dandelion greens and even plantain (though the latter’s not so tasty, below; Plantago major is better used on mosquito bites than on a dinner plate).

The University of California-Davis weed ID site is encyclopedic, and though I wish I could sort by images, once I get to them (on the plant profile pages) the information is some of the most detailed anywhere. They even show the weed in its seedling stage so you can eradicate it then without wondering if it’s your beloved self-sown something-or-other. See what I mean on a sample page (this one is bedstraw, Galium aparine, a common weed here as well).

With 172 species included, the University of Illinois has built an extensive weed database that’s browsable by common or Latin names, but with the added feature of filters (you can sort the list down to a certain flower color, for instance, or one of a series of very specific taxonomic keys, like leaf size, width, or the arrangement of the leaves. This one will get you sharpening your powers of observation.

I own a number of weed guides, some more booklet-sized than book, and was happy to find a full-color one posted free online. “Weeds of the North Central States” is available as a PDF to “page” through, should you happen to live in them there states.

Want to know which ones are so bad they have made their names on the state-by-state “noxious weeds” lists? The real Bad Boys of Weed-dom.

As many weeds as there are, there are apparently as many sources to learn about then. I could go on, but then you’d think I’d grown a bit obsessed with weeds at the moment, wouldn’t you?

April 21, 2010


  1. Laurie says

    All the weeds above are edible and plantain is a fantastic plant for herbal remedies…like bee stings…always handy in the garden!

  2. Laurie says

    I never really want to be completely rid of them :) Gotta keep garlic mustard in check though that’s for sure!

    • says

      You are right, Laurie. They all have their place and uses, and also their downsides. I have never seen more weeds that this year after our wet 2011 and our non-winter. Crazy!

  3. meredith says

    Garlic mustard should be eradicated always. It is a noxious invasive (at least in PA) and out competes many forest spring ephemerals. And violets are nice, but when you have them so thick that they chock out ferns and hostas….then they need to be called a weed. If only they could behanve themselves.

  4. Marian Sole says

    In addition to being invasive, garlic mustard is very hard to eradicate. Its seeds can lie dormant for up to 24 months. The plant emits a chemical which can be seriously detrimental to tree roots. Important to remove without releasing seeds when at all possible. Don’t put in the compost.

  5. Jan C. says

    I realize this is an older topic, but just saw it and needed to put my two cents in! I try to get gardeners in my area to be a little more tolerant of some of the “weeds”. Some of them have very important functions! Many are larval food for butterflies, such as violets, goat weed, plantain, and nettles. I have so many more butterflies and pollinators in my garden since I started including a few of these”weeds”! And then you get more birds who come to feed on the insects…… a never ending circle!!!!

  6. says

    Every time I spot a new weed I try to ID it and see if it’s medicinal or edible and what it’s history is – I love a good reason to spend some quality time on google.

    I love to eat garlic mustard, it hasn’t proven to be as invasive here as it has everywhere else, perhaps something about our soil. Plantain I always welcome since it’s so handy for bug bites, I pull some but most sticks around.

  7. Laura Eisener says

    Alliaria petiolata (Garlic Mustard) is really horrible because even if you dig it up while flowering, it often has enough life to develop seeds before it wilts, so it really is mportant not to put it in the compost unless it is well and truly dead. SometimesI weight it underwater for a few months and then it is safe to put in the compost.

    • says

      Hi, Laura. A big heavy garbage bag (such as one that might have held potting soil or mulch) can also hold it for awhile and it will cook to death before it’s then added to the heap). But you are right: easy to get babies from this one if not very careful.

  8. Lis Braun says

    I LOVE weeds, think they’re awesome, magical and I have a healthy respect for them. Have you ever noticed how they plant themselves in among plants that have similar leaves? Ultimate disguises. Like Microstegium vimineum can hide forever in Deutzia– it actually made me laugh out loud when I saw it. How do they do that? Over and over again they surprise me… as I dig/pull them up. Nature is truly a wonderful thing. As is your blog.

    • says

      Hi, Lis. I love your thoughts on this. Plants do seem to be quite clever, I agree! And thank you for the kind words. I enjoy publishing the blog, and I’m glad it pleases you.

  9. says

    Margaret, Thanks for turning the spotlight on a real plant thug…it got the best of me years ago in PA where it got a foothold behind my back. Now in Vermont I pull it and bag it and this is the best time of year to do it.

    I did have to laugh at the “weed” that tops the list of Pennsylvania’s noxious plants on the USDA list. ??????

  10. says

    This one has hit home with me Margaret! Our yard is infested with weeds…Garlic mustard being one of them! At least they are usually easy to pull out. Some of the weeds we have are spiny (thistles?) and must be removed with care. Others are so difficult to pull completely out even with the aid of a shovel. The roots go down for days and they break easily. I try my best to get rid of the weeds before they got to seed and make more weeds, but it is not always possible — since I refuse to use weed killers on my property.

    My biggest headache is Buckthorn — an invasive tree/shrub that runs along my fence line and pops up in the yard. They are simple to pull when they are young — under 1 ft tall, but once their root systems develop — watch out. The last owners of our property let them grow wild for about 20 years. Our chain link fence has been “woven” with giant buckthorns and there are clumps of them in the yard. I’ve broken 3 shovels, had to go at the roots with a hatchet and have developed a case of tennis elbow from trying to eradicate these pesky shrubs. After three years of war with them, the yard is looking a bit better, but there is a long way to go! Any chance you’ll come help? ;)

    • says

      I’m heading out now, Kate, in my aged Saab station wagon…we should be there in about 2 months or so. :) Good that you are doing it — they won’t get any better on their own and will just make more trouble.

      Hey, Betsy — talk about a silver lining from a dark cloud, huh? Thanks!

  11. Betsy Wells says

    Garlic mustard, I read that you could eat it. So I cooked some, tasted it and promptly threw it away. I had put the unused garlic mustard in a glass of water. The next day I used it in a flower arrangement with pink and white tulips. I got many compliments and, four days later, it is still as fresh as it was the day I picked it. It may be an invasive weed that no one wants in their yard but I have found a use for it.

  12. says

    Garlic mustard, dandelion and violet leaves are delicious in the spring. And nutritious. And medicinal. Lots of Vitamin C, and garlic mustard and dandelion are good liver tonics. Violets are one of my favorites, so I am partial, but I have been using the leaves in salves and teas to help me in my treatment of breast cancer. Plantain is so good as a wound healer, and used to prevent staph. Keep them out of the veggie beds for sure, but they are good friends to have around.

  13. joan packer says

    Garlic mustard is such a nightmare…it seems worse than ever this year. I try to get all of it in the garden area, but its impossible to pull all of it in our woods.
    At least I havent seen any pilea pumila yet!

  14. Kathleen Norris says

    That weed called bedstraw is rampant here in SE CO. Spend so much time weeding that one out every year. Ahhh it loves me!

  15. mikeinportc says

    Garlic mustard – blahhh!!! Makes bittercress and oxalis seem desirable. Whoever brought that here (intentionally?!) deserves some time in horticultural purgatory. (Weeding! ;)
    Dandelion fritters are good, so a few are tolerable. One day, while visiting relatives in Colorado, I was left to my own devices for a few hours. (I was 15) IU decided to help out, and weed the vegetable garden. Being so dry, it was a fraction of what we’re used to , here in the Northeast, despite the very large garden. Seemed a pleasure, compared to the same job at home. Managed to get the whole thing done in a little over two hours. I was quite pleased. :)
    When my cousin got home, she was aghast! I had pulled all the dandelions that she had spent half the summer growing. Apparently, they won’t survive in SW Colorado, without careful nurturing. We salvaged as many as we could find, and replanted them. :)
    was u

  16. Michelle says

    I have a very tall stalk with tiny blue flowers…not sure if its a weed. I would love to able to post a picture!

  17. says

    Garlic Mustard is also a plant that fools a white butterfly into thinking it is its host plant , as the butterfly lays its egg on it, the plant has a chemical in it that kills the butterfly egg. So I yank it as soon as I see it!

  18. DonnaLee Lane says

    On April 25, Honor asked about the weed I struggled with last year. It was literally driving me crazy, so after several hours of research that produced nothing but a headache, I called my weed scientist friend Randy Prostak who is the UMass Extension Weed Speciaiist. If anyone would know what this obnoxious weed was, he would. After a brief description and before sending a digital photograph for his inspection, he said he was virtually sure it was BITTERCRESS (Cardamine hirsute). Seeing the photo confirmed it. A bugger to get rid of.

    He told me that he had received lots of calls from home gardeners, landscape and turf care professionals asking about it. It is a winter annual that germinates in late summer/early fall and since it had already dispersed its seed, there was nothing we could do to eradicate it. He said it proliferated due to the mild winter we had had and suggested that we note its current location(s), look for it in the fall and spot spray the emerging seedlings. Spot spray? That’s a lot of Roundup for my yard!

    I pulled and pulled and pulled. And while I didn’t eradicate the stuff, I had a lot less this year. Good luck with it.

    Margaret: I laughed out loud when I read your paragraph intro “I KNOW, you’re probably thinking: Doesn’t she have anything to do with herself but figure out the names of her weeds, poor lonely woman?” I probably spend more time researching weeds than flowers or veggies. So, you’ve got company — probably a lot of it!

  19. annfsneff says

    We have lots of bitter cress – cardamine hirsute! Thank you for the name, Elizabeth, above. It is amazing how the seeds shoot off the plant. Though it IS fun to pull, before it sets seeds. I read somewhere that weeds perform the valuable function of keeping the soil friable. (!) A Question – Is it the garlic mustard that fills the farm fields with lovely yellow flowers in the spring, before plowing?

  20. Judith says

    Hello Margaret, I love your posts and when the emails come into my IPad, it’s time for a cup of tea and an interesting read.
    Our home and garden is in the Western District of Victoria, Australia.
    Have just read the latest weed stories and am reminded of a good gardening friend who is no longer with us.
    I wonder if I could give you another input on the weed debate….
    Very early in my gardening career we purchased a farming property with a very old established garden and my friend asked me if there were any weeds, in my ignorance and naivety, I replied, ” no, it’s a lovely weed free garden “.
    Guess what erupted all over the garden in early winter, galloped every where and blossomed with bright yellow blooms ??
    Yes, oxalis, sour sop or whatever you like to call it….
    So now, when ever I see the wretched weed I smile and say ” Hello Roma ” !
    But please, could anyone tell me how to free the garden from this pest?

  21. Deb Favero says

    That’s two mystery plants I’ve identified from reading your wonderful weed posts – clearweed and bittercress. Initially I thought bittercress was a geum as its form and leaf shape seemed similar. The few I’d let go never made it to the flower stage when I started seeing them crop up in too many places. It’s a new weed in my Illinois garden, only making its appearance a few years ago.

    I try to pull seedlings since it is so much easier to remove them than the mature plant. I sometimes reference another useful PDF from the North Central States Extension group, published by Michigan State University, “Common Weed Seedlings of the North Central States”. You can find it at http://fieldcrop.msu.edu/uploads/documents/Ncr607.pdf. Many of the weeds depicted are nationwide problems.

    • says

      Hi, Deb. Glad to help — and to commiserate. :) I agree re: seedlings — you can practically just swipe your hand over the soil when they first sprout and wipe out dozens in a single motion. Later? Not so much!

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