How many plants are native to urban areas?

Does this look like a deciduous forest ecosystem?

The emotionally-charged native plant debate only seems to be growing. Well-meaning but misinformed decision-makers continue to institute native plant policies with pressure from special interest groups. Most recently, North Carolina’s General Assembly weighed in on the side of emotional appeal rather than research-based information in mandating “that native trees, shrubs, and other vegetation are [to be] used for landscaping at state parks, historic sites, and roadways.”

Roadways seem a less than ideal place for attracting wildlife

Don’t get me wrong – I love native plants and recommend the use of well-suited native plants in gardens and landscapes. I’m co-author of a book that helps gardeners in the Pacific Northwest choose native species that are likely to thrive in their gardens. But the belief that native plants are superior to introduced species in urban and other unnatural areas is just a knee-jerk reaction to the very real environmental and ecological problems we face. It gives believers a false sense of accomplishment in that they can reverse significant threats such as climate change, wildlife extinction, and pollinator decline simply by using native plants rather than introduced species.

Supporters for this native-only policy list the same tired (and false) reasons that native plants are superior to introduced plants. Here are some of those reasons cited in the North Carolina decision, along with my commentary:

“There are many environmental benefits to native plants, and they are much more likely to thrive in our weather and soils” (North Carolina Department of Natural and Cultural Resources Secretary D. Reid Wilson)

  • The concept of nativity is subjective and many scientists argue that such a subjective division makes it difficult to study, much less discuss, the benefits and drawbacks of introduced plants .
  • This post by Dr. Bert Cregg bursts the bubble on some of the native plant superiority myths.
  • Native soils are not the same as compacted, amended, and otherwise disrupted soils found outside natural ecosystems.
  • There is no research to support that native plants thrive in soils that have been disrupted by development and urbanization.
Even native plants will suffer drought stress if they don’t receive sufficient water

“Native plants are adapted to the state’s environment and more likely to thrive, especially during drought.”

  • Roadways, state parks, and historical sites are not natural environments (though some parts of parks and historical sites could be).
  • Plants that can adapt to disturbed environments are most likely to thrive. Some of these are called weeds.
  • Plants that can survive periods of drought have morphological and/or physiological adaptations for doing so. It has nothing to do with their nativity.

“They support pollinators essential to food production and ecosystem health and boost otherwise declining bird populations that depend on insects associated with native gardens.”

  • One of the basic tenets of ecology is that new resources are exploited by existing members of a food web. What happens with one species of insect or bird or plant is not the big picture – ecology is the big picture.
  • This blog post by Dr. Bert Cregg discusses a paper showing that exotic species can grow more quickly than native plants, but they are eaten more by herbivores.
  • This  blog post looks at some of the research on insectivorous birds that contrasts with the claim that native birds require native insects.
  • The most biodiverse landscapes are those with a high diversity of plants. The vertical structure of a landscape, created by the varying heights of trees, shrubs, and other plants, is crucial for bird habitat. I’ve published both a research article and fact sheet on this topic.

“Native plants, especially grasses, are better able to store carbon, thereby reducing greenhouse gases.”

Grasses and trees both belong in a landscape, but trees store more long term carbon than grasses can
  • Native plants have supercharged photosynthesis? There’s a Nobel Prize waiting for someone to demonstrate that.
  • Trees and other long-lived woody plants are best for storing carbon. Certainly not grasses. And the nativity of the woody plants is irrelevant to carbon storage.
Pacific NW native plants like Gaultheria shallon do not thrive in urban sites where environmental conditions are nothing like natural ecosystems

“Native plants provide habitat for birds and other pollinators, are more resilient, and require less fertilizer and other maintenance.” (Brian Turner, policy director at Audubon North Carolina)

  • Birds and plants have complex and often unexpected relationships. This post discusses a review article on the interaction between birds and those plants who depend on them to spread their seeds.

In June 2023, North Carolina’s Department of Cultural and Natural Resources installed a new 100% native plant garden in front of their DNCR headquarters. In comparing the before and after photos of the site, I’ve got a few observations.

  • If storing carbon is important (as stated earlier), then cutting down all those trees and shrubs (which don’t appear to be invasive species) was an interesting decision.
  • Why not just add a native garden to the existing landscape? That would have increased the plant diversity and retained the vertical structure, which is highly important for biodiversity.
  • If we want stable, biodiverse landscapes in our urbanized environment, we must include the use of introduced species – especially trees. 

“This policy is a big win for birds and everyone who cares about North Carolina’s wildlife. It just makes sense. ” (Brian Turner, policy director at Audubon North Carolina).

  • Nope. It’s a big win for dogmatic belief systems.
Vertical structure and plant diversity creates a landscape that appeals to people as well as wildlife

There are many things that we can do in our gardens and landscapes to maximize biodiversity. Spouting false claims about native plant superiority, garden shaming those who don’t eliminate introduced plants, and forcing communities, cities, and states into lock-step on what can and can’t be planted is not part of that process.

Published by

Linda Chalker-Scott

Dr. Linda Chalker-Scott has a Ph.D. in Horticulture from Oregon State University and is an ISA certified arborist and an ASCA consulting arborist. She is WSU’s Extension Urban Horticulturist and a Professor in the Department of Horticulture, and holds two affiliate associate professor positions at University of Washington. She conducts research in applied plant and soil sciences, publishing the results in scientific articles and university Extension fact sheets. Linda also is the award-winning author of five books: the horticultural myth-busting The Informed Gardener (2008) and The Informed Gardener Blooms Again (2010) from the University of Washington Press and Sustainable Landscapes and Gardens: Good Science – Practical Application (2009) from GFG Publishing, Inc., and How Plants Work: The Science Behind the Amazing Things Plants Do from Timber Press (2015). Her latest effort is an update of Art Kruckeberg’s Gardening with Native Plants of the Pacific Northwest from UW Press (2019). In 2018 Linda was featured in a video series – The Science of Gardening – produced by The Great Courses. She also is one of the Garden Professors – a group of academic colleagues who educate and entertain through their blog and Facebook pages. Linda’s contribution to gardeners was recognized in 2017 by the Association for Garden Communicators as the first recipient of their Cynthia Westcott Scientific Writing Award. "The Garden Professors" Facebook page - "The Garden Professors" Facebook group - Books:

14 thoughts on “How many plants are native to urban areas?”

  1. Thanks for the great article.

    I work on an HOA landscape committee that helps to manage 32 acres of green areas in our Southern California community. We try to use California native species when we can, but the simple fact is that our urban community environment is not a California native environment. Very few native species have been successfully incorporated into our shared spaces. A few homeowners here have created beautiful, mostly native species landscapes in their yards. But it takes a lot of gardening skill to maintain a California native environment in our urban setting. It may be very low water usage but to keep it looking good, it is by no means low maintenance and resilient.

    Can we do a better job of incorporating native species into our community? I think we can, but it needs to be a well thought out blending of native and imported species to get the right balance to meet the community needs of beauty, conservation, and maintenance costs. We have a 1/4 acre butterfly garden using these concepts we are creating soon that we are very excited about.

    Bottom line: An urban environment is not a native environment.

  2. Thank you for this excellent post, Linda! There are myriad ways to create diversity and resilience in a garden, and native and introduced species can work beautifully together to create forage, habitat, shelter, and reproductive capacity for flora and fauna at all scales.

    1. well stated. I was trying to figure out how to explain the type of plants I was hoping to promote in my flegling home nursery, and you just mentioned all the main points! “diversity and resilience in a garden, and native and introduced species can work beautifully together to create forage, habitat, shelter, and reproductive capacity for flora and fauna at all scales” I will try to get in touch for permission to use this quote …

  3. good job on the point by point explanation, but my favorite part is the use of the term “garden-shaming” which goes along with “humble-bragging” I-only-plant-natives.

  4. Two observations from a North Carolinian on this insightful and timely piece.
    The first is that the very well-respected JC Raulston Arboretum at North Carolina State University communicated its opposition to these types of Native Plant laws a couple of years ago, see:
    Secondly, a bill to have the state legislature pass a mandatory law regarding use of native plants on state property is still pending, technically, having been referred to a rules committee earlier this year (SB318). If one clicks through the Audobon Society’s announcements, what is left is some agency policy making requiring that native plants be used at properties controlled by one agency, the Department of Natural and Cultural Resources, with “native” being defined as the Southeastern United States, see: So, fortunately, it is does not appear to be a statewide policy applying to all state property, but it nonetheless serves, as the author notes, as a reminder as to how these types of policies, and laws, have advocates and can be implemented when the native plant advocates are more organized and better funded than the more balanced viewpoint.

  5. While I agree with a lot of what you wrote especially when policy makers skim over the issues that are front and center on the news and don’t take into account what science has found, there are a couple of things I think were missed and your declarations about grass should be qualified.

    First there’s climate change and that means what will grow today in your area based on typical temperatures and precipitation may not be what can grow there tomorrow. The U of Minnesota is studying what the tree topology will be like 100 years from now as tree species move northward and maybe even east or westward. Check out this introductory post about their effort:

    Second, I am not aware of any studies being done regarding how non-native, non-invasive plants homeowners love to grow (seemingly harmless next to natives) present a “foodless plot” for pollinators. I grow plants that originated as far away as Europe, Asia, Africa, and even Australia next to natives to my area and non-natives from other parts of the North American continent. I’m not a scientist so what I say is purely anecdotal but some prolifically flowering plants are not attracting bees, butterflies, nor hummingbirds whereas others do. When you look up a plant’s growing conditions, there are very few that indicate their beneficence to pollinators. If there is enough space dedicated to such “harmless because they’re not pushing out natives” plants, (except humans are a vector to a certain extent) ahem lawn grasses, I think there will be fewer insects, in general, and less food up the food chain.

    Finally, I really beg to differ with you regarding grasses. If you had differentiated between lawn grasses and grasslands, then I’d have understood what you meant.

    T. Jane Zelikova’s research ( is the study of undisturbed grasslands across the country. She’s finding organic matter that goes deep into the soil because their roots grow extensively below the soil level. She has said that grasslands are a better carbon sink than trees and is hypothesizing that the deep necromass below the grasslands may be one tool in the battle to combat climate change. Studies show that there’s more carbon store in the soil below undisturbed grasslands than in similar size forests. Additionally when a forest burns almost all its carbon is released but when a prairie grassland burns only a fraction of the carbon is released because most of it is locked up below the soil. And grass just keeps growing. A forest takes years to replenish.

    Clearly we’re not talking about home gardens and lawns but when there are grasslands of different ilks all over the country, it makes sense to ensure they are preserved and even restored when and where possible.

    Ellen Campbell
    U of MN Extension Master Gardener and Minnesota Tree Care Advocate

    1. Hi Ellen –

      Yes, climate change, if nothing else, will drive what’s considered “native.” That’s why adhering to a subjective philosophy about native vs. nonnative species is not practical. The environment changes: species migrate with those changes. Political boundaries make no difference.

      This blog focuses on gardens and landscapes. While I’ve been deeply involved in ecological restoration and understand it’s importance, that’s not the point of this post. Yes, grasslands can hold a lot of carbon, but so do forests (and they keeping growing too). In this blog’s context, what happens in a home garden or landscape? I know my old garry oaks sequester much more carbon than any of the annuals or herbaceous perennials (including grasses) do. It’s a matter of biomass: the heavier the plant, the more carbon it contains.

      Finally, we need to think about long term storage. Carbon that’s locked up in wood stays “fixed” longer than the carbon in grasses, which is the basis of a grassland ecosystem food web.

  6. An urban garden should be able to have a variety of native and non-native plants in it. If only better choices of non-native plants had been made we might not have the vocal contingent of native plant advocates—all those invasive non-native species have come back to bite us in the collective butt and we’re paying the price—both financially and ecologically. While some native plant proponents can be judgmental and snooty, it certainly is frustrating to see some on the other side desperately holding on to their invasive Vinca minor and Euonymus spp.

    1. I agree with your view here. I am trying to make a home business of selling native plants, and 100% I think its nuts to say native plants are the only “good ones,” or thats all we should put in our yards because of supposed benefits. Plant migration has been going for for some long time now, and not about to stop soon.

      But on the other point, I think probably most people don’t know vinca minor from sword fern, or ivy from oregon grape, and if its in their yard they don’t know what to do about it. Not that they love invasives so much. Its the wholesellers and nurseries that are part or even most of the problem , when they carry and sell their nice pots of butterfly bush, vinca, and nandina. Then those are also picked up by the box stores….

      1. The success of natives within the built environment really depends on where you are planting and the challenges those plants will have to face. Our experience with trees is that many natives are just not urban tolerant enough to survive the challenges the built environment inflicts on them.
        Those challenges instigated extensive research that resulted in a number of databases that list the forest trees that are urban tolerant.

        The overriding criteria is that whatever you select, it must not be invasive but, following that, it must be able to grow well in the urban conditions we cannot mitigate.

        1. It was depressing to have to cut down our huge native pin oak (Quercus palustris) which, like scores of mature trees planted in suburban St. Louis, succumbed to hypoxylon canker ( and there’s been a campaign by the Missouri Department of Natural Resources “plant an oak but not a pin oak” another example of put the right plant in the right place. Unfortunately in my neighborhood this was knowledge that should have been used 30 years ago!

  7. The vast majority of plant species of foreign origin that have been introduced to North America have not become pests here.

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