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 paled until recent years. Lately, on days not conducive to outdoor work, I’ve been studying up 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. The Rutgers weed tool is generally appropriate for my region, and  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 plant profiles of edible weeds on his website, if you’re hungry, with Brill’s advice 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.

The Virginia Tech and Virginia Cooperative Extension’s weed identification tool helps you narrow your choices, too, by similar methods. And Clemson University had a weed-identification search tool, too.

Likewise, the Integrated Pest Management website of the University of California has a great weed reference database.

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 sample PDF to “page” through, should you happen to live in them there states, and you can buy the whole thing for $5 here.

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.

weed bookAs many weeds as there are, there are apparently as many sources to learn about then, and if it’s old-school you want–with a full-fledged field guide at your side–I use this one (above), or most often of all the best one for my region, “Weeds of the Northeast” (affiliate link) co-authored by Richard Uva (below). I could go on, but then you’d think I’d grown a bit obsessed with weeds at the moment, wouldn’t you?

some of my first-name-basis weeds, and control ideas

  1. Manugian Liz says:

    Love your blog and your podcasts, Margaret. Thanks for sharing your knowledge and talents!

    I do not see any reference to the dreaded Lesser Celandine (Ranunculus ficaria L.) or fig buttercup, probably the most invasive noxious plant imaginable impacting large parts of the US …. getting rid of it is proving almost impossible. I am an avid gardener with several acres here in Memphis. My entire front lawn and flowerbeds are smothered by this weed, which consumes my thoughts 24 hours a day. Having been herbicide free for decades, I am now having to blitz my garden with repeated spraying of 2-4-D. I did the same last year, with no noticeable results. Next year, I believe I am going to have to resort to bare-rooting all the plants and then blitzing with multiple treatments of Glycophosphate . I wonder if you have any other suggestions, apart from ‘move’ suggested by a friend at Birmingham’s Botanic Garden. The problem with this weed is that it looks so attractive and is an ephemeral, and most people (including myself) initially think what “harm could it do, it is gone by April?”. But its deep roots, covered with thousands of corms/bulblets, continue to grow/spread underground, forming an impenetrable mat through which nothing will grow. Spread by flowing water, birds and probably lawn mowers ..
    Any help/suggestions would be so appreciated!

    1. Lisa Talbot says:

      I was just seeing some progress on poison ivy and was ready to tackle buckthorn and then… lesser celandine took over my weed radar. And our parkway. And is clearly creeping into our property. The advice I’ve been given sounds akin to napalming half of our property, and I’m not ready to do that, but hand weeding sounds arduous. But perhaps a combination (herbicide on parkway, hand weeding in areas where there are also lovely patches of trillium and other natives)? I’m in Lake County, IL 5b/6a.

    2. Justine Beaudoin says:

      I have the lesser celandine, too. After conferring with a scientist working with my county I have resorted to 53% glyphosate application. I’m in my 3rd year with it and making some progress. I apply it with a foam paint brush. Never in windy conditions, never if it is blooming. I’ve battled lots of invasives but this one is, by far, the worst. We need a support group. My friends avoid me in early spring because all I can talk about is how much I hate the stuff.

  2. Allison Kelsey says:

    My fave ID book right now is Wild Urban Plans of the Northeast by Peter Del Tredici. I live in Philly, and some names I knew from the Midest, and one horrible horrible vining weed all over our alley I needed to find the name of and it was in this book.

  3. M K Arnberg says:

    Weeds of the Northeast has been my go-to for many years… my older copy does not ID Garlic Mustard, but there is enough of it here in Eastern MA that I have learned what it is and added the info to my “bible”.. I always recommend this book when I give a weed lecture or even visit a garden. Teachers may retire, but the never quit teaching something… This book is a keeper!

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