University of Maryland Extension

Part 7: The Future


Finding Appropriate Species for Native Plant Projects in Maryland’s Ecoregions

There isn’t one great resource for Maryland gardeners to find out which plant species are native to their part of the state.  Below I’ve outlined a process you can follow to create a list of plant species that make good candidates for your native garden project. 


Look at the site conditions where you will be gardening.  Why?  Plants are native to conditions.  Characteristics such as soil texture, pH, moisture, topography, and aspect will affect the plant species that would be native to your site.  Here are two great resources for accomplishing this:

  • Get your soil tested.  (See resource list below).
  • Check out your local soils at  All you need to get started is a street address (and really, not even that).


Determine your ecoregion. You can download the map of EPA Region 3 Level III and IV Ecoregions from


Look for a natural community within your ecoregion that has site conditions similar to the conditions where you will be gardening.   This natural community can serve as a role model.  Learn which plant species are native there.  Observe how the plants are arranged with respect to each other, what relationships are present?  Visit the natural community at several different times of year, and build a plant species list.


Build up your botanical library.  Two books you will definitely want access to are the Woody Plants of Maryland, and the Herbaceous Plants of Maryland.  In addition to helping you identify species, these books contain helpful comments about where the species are found.

See the class resources page for websites, books, articles and more that can help you determine what is native in your area.

The above text is also available as a handout (click here).

Defining "Native Plant"

Today's lesson takes about 1 hr 15 minutes, and has been split into three parts to make the video files more manageable. 

The first video (35 min) discusses existing definitions for "native plant" and presents a first draft definition for the Maryland Master Gardener program:

Can cultivars of native plant species be considered native plants?  The second video (34 min) answers this question, and provides a nine-point comparison of cultivars and native plants:

Shopping for Native Plants

You’ve selected a plant species that is native to your ecoregion and your site conditions, it’s just perfect for your garden project.  Now you’d like to purchase plants or seeds that are locally native and locally grown.  That can be hard to do, but here are some tips to help you successfully navigate through your shopping experience. 

What is a native plant product?

We've talked about the definition of native plant species, but what about native plant products?  In addition to being a member of a native species, native plant products are:

  1. Genetically appropriate (to cross-pollinate with other members of the species in its area and to perform well within the ecoregion and under the proposed site conditions),
  2. Genetically diverse (each according to their own species),
  3. Not kept in cultivation for more than three generations, and
  4. Native seeds are AOSCA certified.

When trying to decide if a particular product is really a native plant product or not, ask yourself, "Is this genetically appropriate?  Is it genetically diverse?"  Only native plant products can provide the gardener the benefits of working with native plant species.

How Local is Local?

First of all, what would be considered locally native?  Ideally scientific studies would be available to tell us how far away we can go when shopping for native plants.  It will be a long time before that’s the case though, because a study has to be done for every species.  In the meantime, here are some often-applied guidelines:

  • Plants should be sourced from within the same Level III ecoregion as the planting site,
  • The parent population should come from site conditions similar to the planting site, and
  • Plants in cultivation for more than three generations are not native.

How to Tell if Plant Products Are Native

Seeds: For bulk seed, Maryland participates in the AOSCA seed certification system.  In this system, native seed is called “source-identified”, and once it’s inspected by the MDA, it receives a  “yellow tag” indicating the seed’s provenance and the number of generations is has been in cultivation.  When purchasing native seed, you can rest assured that the grower has taken measures to capture and preserve the genetic diversity of the parent population.  This is an example of a yellow tag for gray goldenrod seed wild collected in the Patuxent watershed and produced by a grower in Anne Arundel County MD:

Image of a yellow tag that indicates the source-identified status, provenance and production area for the seed.

Plants: Maryland does not have a certification system for locally grown, native plant material.  Without that, these are the best things that you, as a consumer, can do:

Look for voluntary labeling that indicates

  • provenance
  • measures taken to preserve genetic diversity
  • generations in cultivation
  • Shop at trusted nurseries with knowledgeable staff, and when you need to, ask questions.
  • Ask where the plant was grown (where the wholesaler is located)

If you cannot find locally native plants at your usual retail nursery, try a nursery that only sells locally grown, locally native plants.  Such nurseries indicate this specialization clearly on their websites.

Consider attending one of the annual native plant sales at a local botanical garden.  These are usually attended by several native plant vendors.

How to Spot Non-Natives:

Products that are not native include those that have a

  • Cultivar name or Trade name
  • Wholesaler who is not local
  • Certification from outside your ecoregion
  • Plants that are labeled "native" but don't say "to..."
  • Plants/seeds that are just labeled "wildflower"

Plan B

What to do if you cannot purchase a locally grown, locally native version of the species you are looking for?  Here are some options:

  • Contact the nearest native plant nursery and ask them to contract grow it for you,
  • Consider a different species,
  • Participate in or even organize a plant rescue.  In addition to development sites, if you know some farmers, consider farm fields and farm roads as potential sources of common native trees and shrubs,
  • Plant propagation – grow your own,
  • Consider procuring species that are native to your region but with provenance and/or production from an adjacent ecoregion if conditions are similar there,
  • You might consider purchasing a cultivar (nativar) if supporting wild plant populations is not an objective.  To be cautious, only purchase
    • Sterile nativars, or
    • If the species is very common your area, a fertile nativar.
  • Consider purchasing a locally-grown, sterile alien plant species.  When purchasing alien species, if you purchase locally-grown ones, it greatly reduces the risk of importing invasive pests, supports your local economy, and reduces the carbon imprint of your gardening activities.

Sustainable Landscaping and Native Plants

The 3rd and final video (37 min) discusses the larger concept of sustainable landscaping, of which using native plants is but one part. 

Puzzler Answer:

In the previous lesson you were asked, "Suppose you were selecting plants for a native garden just east of Worcester County. If you use the arrival of the Original Americans as the basis for defining which species are native to the area, which ones will you select for the garden?  How would your selection influence whether the new garden was a low input, sustainable landscape project?  The answer will appear in the next lesson."

The county east of Worcester is currently the Atlantic Ocean.  19,000 years ago, however, when much water was tied up in glacial ice, the sea level was much lower.  Then the area was part of a boreal forest.  Spruce and hemlock would have been common canopy species.  These would make poor choices for a native garden in salt water, in fact, even the concept of native garden seems a little out of place!


A parting assignment for you, and one I hope you will enjoy as you prepare for the Post-Course shopping exercise, is to visit the website of a REAL native plant nursery.  Our role model comes from Washington state.  Surf the site (click here), it's not very large, so this may take less than 15 minutes.  What specifically do you see on this website that makes you feel comfortable that the nursery is growing and selling plants that are native to their ecoregion?


Here's a class handout for you.  It contains resources that will be useful to you in your extension work, including references you may want to get and websites that can help you build lists of plant species that are native to your part of Maryland.  (click here)

Parting Remarks

Well, that concludes our introduction to native plants.  Many of you probably have other areas of focus for your extension work and don't need to dabble in this topic further.  If you've got native plant fever, however, as so many of us do, please join us for classes on how to use native plants in the landscape.

Please turn to the following page and take the Mock Shop Exercise again.  This will allow you to practice some of the principles you've learned during this course, and allow us to evaluate how effective the class is.

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