University of Maryland Extension

HGICs Invasive Plant List: A Compilation of Lists from Maryland and Adjacent States

Are you considering purchasing some plants and concerned about their potential invasiveness? Whether you’re a business owner shopping for plants to resell, or just looking for something to put in your own yard, our list will save you time. We’ve compiled data from a dozen of the region’s most well-respected sources, so you can find it all in one spot.

Table 1.
Click on the list below to open a 102-page pdf file. (Use an alternate web browser if you have trouble viewing table) Updated 4/11/17.

invasive plant list

If you do find a species on this list, it means that at least one authoritative resource considers it invasive.

Sources for Invasive Plant Species List. This link will open a 6-page pdf. Updated 4/11/17.
Thank you to Judy Fulton for her work on compiling the information in these documents.

How the List was Developed

This document has been developed as a convenience for you. It does not contain any original research on the part of UME. Instead, it is a compilation of existing lists published by respected sources in Maryland and adjacent jurisdictions.

Each row of the spreadsheet contains information obtained from the reference cited in the “Data Source” column. If a species was present in multiple references, it has multiple rows on the spreadsheet. This allows you, the reader, to evaluate the gravity of the situation and the credibility of the data sources for yourself.

If you are aware of additional authoritative sources or vetted/peer-reviewed literature that should be added to our list, please email it to stangren@umd.edu.

FAQs

Q: What can I do to be a role model in my community?

A: Identify and remove invasive plant species whenever and wherever possible. You could replace one invasive species in your yard every year, or you could tackle them all at once. For added environmental benefit, some people like to replace invasive with native plants. Do whatever is most comfortable for you, and share information with your friends, family, and neighbors.

Q: Does this list have any regulatory authority?

A: No. This is merely a compilation of other lists. Some of those have regulatory authority and some do not, please see "sources" for more information. 

Q: What if I don't find the species I'm looking for on the list?

A: Possible explanations include:

  1. Your species may be on the list (see Table 1. above) but under a different common or scientific name. This is very common. To find out, use the search function (Ctrl + F, Cmd + F on Mac) and type the scientific or common name that you know in the box that appears. If the plant is listed, this should take you to it.
  2. The species isn’t invasive and never will be.
  3. The species is in the early phases of invasion, where it may stay or may explode. It is common for species to be absent from the listing while under debate by authorities.
  4. The species could be a candidate for invasive status in our region, but our sources have not yet added it to their invasive species lists.
  5. The species is invasive in other regions, but invasiveness here hasn’t been reported. This is common in the early phases of invasion, and for species that simply are not adapted to our climate.

Q: What about cultivars?

A: If our sources have mentioned specific cultivars, you will find that information in our “Notes” column. While it is certainly our hope that many cultivars are not invasive, vetted/peer-reviewed research studies on cultivars, generally, are not available.

The question is also more complicated than it seems on the surface. For example, some cultivars are not invasive in and of themselves, but when other cultivars of the same species are introduced, they begin to self-sow prolifically. In an even more bizarre plot twist, some cultivars of native species are so aggressive that they, too, warrant placement on an invasive plant list. In that case, the cultivar would be listed, but the species would not.

Unfortunately, the absence of a cultivar name on our list simply reflects a lack of information.

Q: I grow one of the species on the list for food. What should I do if I want to keep my plants but protect the environment at the same time?

A: Fortunately very few herbs, fruits, and vegetables are on the list. If you are growing an invasive food plant, you've already taken the first step, you've made yourself aware of the plant's invasiveness. There are very few food plants that are so invasive that you can't keep them under control once you are aware of their wandering ways. Take whatever measures are necessary to keep them from spreading to natural areas. Mints, for example, can be grown in containers. Cover berries with netting to keep birds at bay. Flowers can be removed before seeds develop. When it comes time for you to move away from your property, make sure that the species has been eradicated. There are only a few food species that are so aggressive and so hard to kill, that you probably can't manage the challenge once you are aware of it.

Q: Where can I get more help?

A: We can help you understand the list, select a strategy for killing your invasive's, or select replacement plants. Here's how:

In person - Ask A Master Gardener! UME Master Gardeners are also transitioning away from the use of invasive species, and they can help you to do the same. You can even bring plant samples if you like!

By email - Type up your question and send it to HGIC's Gardening Experts. You can even add photographs if you like!

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