Chicago's Invasive Plant List

On May 9, 2007 the City Council passed the Invasive Species Ordinance
that made it unlawful to possess certain invasive plant and animal species. At
the time the plants on the list were mostly aquatic plants, but this
year the list was updated to include land-based invasive plants. The
updated Invasive Species Ordinance now makes it illegal to; “import,
sell, transport, own, keep, release, introduce, or otherwise possess in
the City of Chicago,” the following plants of March 2009:

Chocolate Vine, Elegans Porcelain Berry Vine, Wild Chervil, Oriental Bittersweet, Japanese Hops, Lyme Grass, Privet, Amur Silver Grass, Princess tree, AmurCorktree, Japanese Corktree, Japanese knotweed, Sawtooth Oak, Lesser Celadine.

Nothing on the list growing in my garden, how about yours? Will you
remove any these plants if they are currently found in your garden?
Besides Chocolate Vine (Akebia quinata ) nothing on the list that I
would go out of my way to buy or grow. The list of plants is rather
boring, if you ask me. The land-based plants chosen were selected
because they are in trade but not yet widespread. I guess the idea here
is to deal with them now, rather than in the future when they could be
a problem.

While researching a weed in my garden I came across the City of Chicago Land-based Invasive Plant Brochure (pdf)
which is where the information above came from. I discovered that I’m
harboring at least three species of invasive plants in my own garden.
While not regulated by the City, the three I’m growing are discouraged.
My three offenses from this list are; the orange daylily, Perennial Sowthistle and I believe now, Canada Thistle. Although none of the recently blooming weeds in my garden were on the list.

Canadian Thistle Chicago Invasive Plant List at Chicago Garden.png

season is the first year Canada Thistle was spotted growing in my
garden and I’ve let it grow partially because of laziness, but mostly
because of curiosity of what the blooms would look like and what it
would attract in the garden. One day while photographing some bees and
beetles that were visiting the lavender colored blooms I discovered
that the flower is sweetly scented. Now that I know just how noxious a
weed Canada Thistle is I don’t think I’m going to let it go to seed or spread in
the garden.

If you have plants growing in your garden and you
want to know if they are invasive or not, look through the brochure linked
above. It has 16 pages of good information and non-invasive plant
suggestions to replace the invasive plants now banned in Chicago along
with 26 common invasive plants you should avoid.

Update: There’s also a list of invasive plants for the Chicago Region put together by the Chicago Botanic Garden.


Leave a comment
  • The city of Ann Arbor has two invasives lists: The really, really bad and the just bad (well, that's what I call them, they don't!). The really, really bad list contains the top offenders, which the city is actively elimnating from natural areas:

    Tree and shrubs:
    Norway Maple (Acer platanoides)
    Tree-of-Heaven (Ailanthus altissima)
    Autumn Olive (Elaeagnus umbellata)
    Honeysuckle (Lonicera spp: maackii, morrowii, tatarica, x bella, & xylosteum)
    Common Buckthorn (Rhamnus cathartica)
    Glossy Buckthorn (Rhamnus frangula)
    Black Locust (Robinia pseudoacacia)
    Multiflora Rose (Rosa multiflora)

    Vine and groundcovers:
    Oriental Bittersweet (Celastrus orbiculatus)
    Purple Winter Creeper (Euonymus fortunei)
    Japanese Honeysuckle (Lonicera japonica)
    Myrtle, or Periwinkle (Vinca minor)

    Herbaceous species:
    Garlic Mustard (Alliaria petiolata)
    Bittercress (Cardamine impatiens)
    Spotted Knapweed (Centaurea maculosa)
    Canada Thistle (Cirsium arvense)
    Lily-of-the-Valley (Convallaria majalis)

  • In reply to gardenfaerie:

    Lily-of-the-Valley is on the really, really bad list? I think I like your list a lot better than our invasive plants list.

    The other day I was a Japanese Honeysuckle growing in an abandoned garden near my house. I think I'm going to go in there and yank as much as I can out of there before it ends up in my garden.

  • In reply to gardenfaerie:

    I pulled a ton of Oriental Bittersweet out of our alley last year. One can see why people brought it in; it's a beautiful plant. We have Japanese Knotweed taking over our sideyard. I pull it as fast as it grows, but my neighbor likes "the way it fills in the area" and I haven't been able to convince her to pull it. Maybe now I can tell her that it's illegal. However, can I be fined if the stuff has invaded my yard? I certainly didn't plant it.

  • In reply to naxn:

    Hi Xan,

    Good question. I wondered the same thing myself last night as I was posting this and made a mental note to call around today and see what the punishment would be for growing the banned plants. Unfortunately, I didn't get around to it but I'll try to call around on Monday and see if I can get an answer.

  • In reply to naxn:

    Hi Mr. Brown Thumb and friends,

    Fear not... the Chicago Department of Environment (leading the inspection and enforcement of the City's invasive species ordinance) will be regulating the sale of these species at garden centers across the city. However, residents can play an important role in preventing the spread of invasive species by removing regulated and discouraged species from their yards and by raising awareness among neighbors and friends. More information can be found at

    Thank you, Mr. Brown Thumb, for highlighting the City's efforts to prevent and control invasive species in your wonderful blog!

    Kind regards,
    Lyndon Valicenti
    Consultant for Chicago Department of Environment

  • In reply to lvalicenti:

    Hi Lyndon, Thanks for signing up for an account so you can pass on this information to us.

  • Technically it could spread if birds eat the seeds and then poop the seeds outside of the garden. But you're right. I've been watching them in a neighbor's yard for the past few years and have noticed how they can't even been able to fill a raised bed they are planted in.

    Now that you mention it, I don't think I've ever gotten close enough to Lily-of-the Valley to actually smell the scent. I'll have to do that next spring when I spot them. Thanks for the tip!

Leave a comment