Frequently Asked Questions

About Native Plants

What is a native plant?

A native plant is one which has evolved in the habitat in which it is found, as part of a complex, interrelated ecosystem including both living and non-living elements, such as climate, soil type, etc. Typically a plant is considered native in the Americas if it was present in its current location before the arrival of Europeans after 1492.

For more information, search “what is a native plant?” on the Lady Bird Johnson Wildflower Center from which the following was obtained.

Source  http://www.wildflower.org/expert/show.php?id=972

“…the best native plant definitions are the ones that incorporate the provenance and evolutionary history of a plant group or lineage. Take, for example, the definition offered by Wasowski in The American Gardener[1] in 1998, “Native plants should be defined as those that have evolved and adapted to a specific location and have remained genetically unaltered by humans.” This definition takes into account time and place, as well as the human element. More importantly, it implies a connection between generations through a shared evolutionary ancestry.

So what is a native plant? It is actually pretty simple to summarize Wasowski to define a native plant as … a plant that occurs naturally in the place where it evolved.” (Dr. Damon Waitt)

What ecoregion is Williamson County in?

That depends. Where do you have property? Williamson County includes at least three distinct ecoregions (and possibly four), each with differing soil characteristics and overlapping sets of native plants, or you could just consider it a part of Central Texas.

You can visit NPSOT’s state site which has a map showing all ecoregions across all Texas counties.

If you visit the Texas Parks and Wildlife (TPWD) Wildlife Diversity website you will find that Texas is mapped according to the underlying  soil and geology of ten distinct ecoregions, and that Williamson County is mostly divided into the Cross Timbers and Prairies ecoregion to the west of Interstate 35 and the Blackland Prairies ecoregion to the east of I-35. The Post Oak Savannah region captures a relatively small area in the southeastern tip of the county.

What about the possible fourth ecoregion? In 2008 the Williamson County Conservation Foundation issued their plan for protecting species’ habitats while helping people make full use of their land. Their mapping differed from TPWD by dividing the region generally to the west of I-35 into the Balcones Canyonlands and the Limestone Cut Plain. The eastern parts of the county were designated as parts of the Blackland Prairies and the Post Oak Savannah ecoregions. The Balcones Canyonlands are described as part of the Edwards Plateau ecoregion, while the Limestone Cut Plain corresponds to the Cross Timbers and Prairies ecoregion. The primary focus in the WCCF plan is on endangered animal species, and native plants are considered primarily in the role of habitats for the Golden-cheeked warbler.  The page in the WCCF plan, from 2008, with just the ecoregion map can be viewed here.

What plants are native to Williamson County?

That depends. Where do you have property? Williamson County includes at least three distinct ecoregions (and possibly four), each with differing soil characteristics and overlapping sets of native plants, or you could just consider it a part of Central Texas. Where you search for guidance can also result in differing recommendations for species of native plants.

If you use the  Recommended Species interactive map on the Lady Bird Johnson Wildflower Center website, you will see that they have divided Texas into six regions, and that Williamson County is included under Central Texas. If you are not trying to recreate or restore a wildscape, you might prefer this listing of plants that are commercially available for use in planned landscapes.

You can visit NPSOT’s state site with a map showing all ecoregions across all Texas counties.

If you visit the Texas Parks and Wildlife (TPWD) Wildlife Diversity website you will find that Texas is mapped according to the underlying  soil and geology of ten distinct ecoregions, and that Williamson County is mostly divided into the Cross Timbers and Prairies ecoregion to the west of Interstate 35 and the Blackland Prairies ecoregion to the east of I-35. The Post Oak and Savannah region captures a relatively small area in the southeastern tip of the county. These lists of plants native to the ecoregions would be more useful if you are trying to restore the local flora and habitat. The lists might also be a better fit for established plants in terms of water needs, cold hardiness and heat tolerance.

You can find information elsewhere on this website under the Dig Deeper menu item at the top of the page, including plants recommended for Williamson County and chapter information you can download.

What about the possible fourth ecoregion? In 2008 the Williamson County Conservation Foundation issued their plan for protecting species’ habitats while helping people make full use of their land. Their mapping differed from TPWD by dividing the region generally to the west of I-35 into the Balcones Canyonlands and the Limestone Cut Plain. The eastern parts of the county were designated as parts of the Blackland Prairies and the Post Oak and Savannah ecoregions. The Balcones Canyonlands are described as part of the Edwards Plateau ecoregion, while the Limestone Cut Plain corresponds to the Cross Timbers and Prairies ecoregion. The primary focus in the WCCF plan is on endangered animal species, and native plants are considered primarily in the role of habitats for the Golden-cheeked warbler.  The page in the WCCF plan, from 2008, with just the ecoregion map can be viewed here.

plant list of both native and exotic species found at the Balcones Canyonlands National Wildlife Refuge can be found deep within the Balcones Canyonlands website.

Why should we use native plants?

The National Park Service page that provided the text below is no longer available at its original link… but all of these reasons still apply!

“Native plant species provide the keystone elements for ecosystem restoration. Native plants help to increase the local population of native plant species, providing numerous benefits. There are specific associations of mycorrhizae with plants, invertebrates with woody debris, pollinators with flowers, and birds with structural habitat that can only be rebuilt by planting native plants.

Advantages of native plants:

  • add beauty to the landscape and preserve our natural heritage
  • provide food and habitat for native wildlife
  • serve as an important genetic resource for future food crops or other plant-derived products
  • help slow down the spread of fire by staying greener longer
  • decrease the amount of water needed for landscape maintenance
  • require very little long-term maintenance if they are properly planted and established
  • produce long root systems to hold soil in place
  • protect water quality by controlling soil erosion and moderating floods and droughts”
What is an invasive (or “exotic” or “introduced” or “adapted” or “naturalized”) plant?

Invasive plants are plants which grow quickly and aggressively, spreading and displacing other plants. Invasive plants are usually introduced by people either accidentally or on purpose, into a region far from their native habitat. Invasive plants are often referred to as “exotic,” “alien,” introduced” or “non-native” species. In their natural range, these species are limited by environmental, pest or disease conditions, keeping these species in balance within their ecosystem. When introduced into an area where these limitations are absent, some species have the ability to become invasive. These are the species we are concerned about in conservation.

(source: http://www.dcnr.state.pa.us/forestry/plants/invasiveplants/ [access date 07/22/2013])


For specific information about invasive species in Texas, visit https://www.texasinvasives.org

For a listing of invasive and noxious plants found in Texas, visit the USDA: https://plants.usda.gov/home

How can I identify this plant?

One good place to start is the Native Plant Identification Network or NPIN, hosted at the Lady Bird Johnson Wildflower Center website. Enter the characteristics that you know about the plant, search, and then check your specimen against the results of your search to find a likely suspect. You can also find resources under Dig Deeper, in the menu bar above.

Several useful databases are collected on the Texas A&M Know Your Plants website. 

You can always come to one of our meetings on the second Thursday of each month at 7:00 p.m. at the Georgetown Public Library and ask one of our members what they think.

Also, thanks to our chapter’s donation of books, you can find books on identification of native Texas plants (and more) at all Williamson County area public libraries.

Planting Natives

Why should I plant native plants?

With habitat disappearing at an alarming rate, you can help provide wildlife with an oasis of the habitat they need to thrive.  The native plants that you use can meet the needs, including food and cover, of native wildlife without causing long-term damage to local plant communities. With the right diversity of native plants in your urban landscape, you can provide:

  • Protective cover for many animals.
  • Seeds, nuts, and fruits for squirrels and other mammals.
  • Seeds, fruits, and insects for birds.
  • Nectar for hummingbirds and butterflies.
  • Larval host plants for butterfly caterpillars.

(source: http://www.ncsu.edu/goingnative/whygo/benefits.html [access date 07/22/2013]).

Do you have tips for working with an HOA?

See How to Work Constructively WITH Homeowners Associations, one of the chapter resources listed in NPSOT-Wilco PDF Downloads under Dig Deeper.

Which native plants are recommended for Williamson County?

A number of sources can help you select native plants suitable for your area in Williamson County, e.g., Blackland Prairie vs. Edwards Plateau.

When info for a particular plant says “Water Use: Low” and “Soil Moisture: Moist” is that a contradiction? Are those two things different?

Low water use vs. moist soil can be confusing.

Low water use = regions of low annual rainfall.

Moist soil = not wet soil as in not at the bottom of the ditch or along the creek bank. 

Here’s an example. Eryngium leavenworthii, False Purple Thistle, is a tap-rooted annual in the carrot family, shown in the Lady Bird Johnson Wildflower database as low water use, moist soil. It will take advantage of a rain to sprout and form a tap-root to hold moisture.  And it seems to take advantage of surface water moving down-slope.  That means in nature you will see it growing in the path that water follows as it flows down a slope; rarely at the top of a hill.  In a low-rainfall natural landscape, it is amazing to see the subtle difference just a little water makes.

Where can I purchase native plants?

NPSOT-Wilco does not endorse businesses but see our Dig Deeper page for a list of area resources we’ve put together to see where some of our members have found native plants for purchase. 

Our chapter holds native plant sales twice yearly, in the spring and in the fall.  We announce NPSOT-Wilco plant sales in our Blog and on Facebook.

You can find native plants at the Lady Bird Johnson Wildflower Center’s spring and fall plant sales.   See the LBJWC website.

You can search for plants in the Lady Bird Johnson Wildflower Center’s plant database where plant descriptions sometimes include the names of local area sources.

Other Questions

How can I learn more about native plants?

You can do any or all of these things to learn more about native plants.

  • Attend NPSOT-Wilco chapter meetings, free and open to the public.  See our Wilco Home page for planned topics.
  • Enroll in one of our courses in the Native Landscaping Certification Program.
  • See the information available on our Dig Deeper page.
  • Join the Native Plant Society of Texas!  There are chapters across the state.
How can I find a certified arborist?

NPSOT-Wilco does not endorse businesses, however, information from the International Society of Arborists (ISA) might help your search.

See the ISA menu item “Find an Arborist” at  https://www.isa-arbor.com/For-the-Public.