Invasive scotch broom, left, crowds out native species. Similarly colored and just as lovely, the native northern spicebush, right, provides nourishment and habitat for native species. (Photo courtesy Denise Williams/iNaturalist CC BY-NC, Photo by Will Parson/Chesapeake Bay Program)

Humans have always had a love affair with flowers. Around the world, we have followed that flower passion with reckless abandon, planting foreign beauties that add unique flare but cause widespread ecological woes.

These exotic imports were at first simply non-native, but they have become invasive species: non-native plants that cause harm to the ecosystem. Here in the Chesapeake region, invasive plants might wreak havoc for birds and choke out native vegetation like the Asian honeysuckle, kill off native butterflies and suppress spring ephemerals like garlic mustard, or play host to the boom in ticks like Japanese barberry. The plants themselves are not inherently bad, but they cause devastation in a foreign environment without natural checks to keep the balance.

Lured by a pretty face, we have deliberately invited vipers to the nest—but luckily, our region grows local stunners that also turn heads. Before your next plant purchase, let yourself be introduced to regional native alternatives that are just as breathtaking as the invasives.

Invasive: Princess Tree

Displaces natives, spreads easily

Native: Redbud

Hosts insects and birds

Purple and pink flowers adorn bare branches

Invasive princess tree, left, and native redbud, right (Photo courtesy Shahrzad Fattahi/iNaturalist CC BY-NC, Photo by Will Parson/Chesapeake Bay Program).

Though gorgeous in its own right, the princess tree is incredibly invasive. It insinuates itself everywhere it can, displacing native species as it spreads along stream banks and forests and pops through infertile ground. It creates buds on stems and roots, sprouting from each to live again after cutting, fire or bulldozers. A single tree produces 20 million seeds which are then spread far and wide by wind and water.

If you are looking for a tree of equally incredible color that can stop you in your tracks with its beauty, meet the redbud. As winter ends and green leaves appear across the landscape, this tree stands out as it erupts in rosy buds all over its bare branches. Foregoing leaves in favor of full floral, the redbud will bloom through April and then don a coat of slightly heart-shaped reddish leaves which change to green, and then yellow, as the seasons progress. Redbuds provide nectar for insects and seeds for songbirds, and flower as early as three years old.

Invasive: Lesser celandine

Displaces natives, spreads easily

Native: Green-and-gold; Marsh marigold

Hosts insects and birds

Yellow flowers dot green clumps of leaves on the ground

Invasive lesser celandine, left, and native green and gold, right (Photo courtesy Rush Hanks/iNaturalist CC BY-NC, Photo by Will Parson/Chesapeake Bay Program).

Few views are as smile-inducing as a sea of cheery yellow flowers perched atop dark green leaves in the woods. In the Chesapeake region, two of these plants are innocuous and one is an invasive, artfully deceptive little monster. The two native options in the watershed grow in different climates; green-and-gold appears in forested areas and marsh marigold in wet, marshy areas. Both offer wildlife benefits and will spread in moderation. Lesser celandine, being a foreign visitor, doesn’t have the checks on its growth that would keep the system in balance. Most of the insects, diseases and other animals that might recognize it as food and temper its growth are back home in Europe, so lesser celandine flourishes here in the Chesapeake. Lesser celandine also emerges earlier than most of spring ephemerals, taking over the forest floor in a heavy mat that allows nothing else to grow.

Invasive: Japanese wisteria; Chinese wisteria

Pulls down trees

Native: American wisteria

Hosts butterflies

Purple flowers blanket trees

Invasive Chinese wisteria, left, and native American wisteria, right (Photo by Caitlyn Johnstone/Chesapeake Bay Program, Photo courtesy csglenn/iNaturalist CC BY-NC).

While we have three species of the genus Wisteria in the Chesapeake region, only one is supposed to be here. American wisteria is a well-behaved vine that grows to about 30 feet, flowers in beautiful purple clusters, brings splendor as it twines around trellises and plays host to skipper butterflies. The two Asian wisteria species introduced to our region are heavier, thicker, more aggressive and they don’t so much gently twine around trees as strangle and constrict them. Invasive wisteria grows to 80 feet and smothers the canopy, pulling down full grown trees. For a beautiful display that enhances rather than destroys the landscape, opt for native American wisteria.

A word of caution: while native plants are well-suited to their home ecosystem, don’t be lulled into thinking of all natives as tame. Plants are living things with some incredible defenses, and the seed pods of wisteria (including our native) are toxic. Do not partake!

Invasive: Star of Bethlehem

Displaces native species, toxic

Native: Spring beauty

Hosts pollinators, edible

White and purple flowers grow from a small plant

Invasive Star of Bethlehem, left, and native spring beauty, right (Photos by Will Parson/Chesapeake Bay Program).

Star of Bethlehem is another adorable floral escapee that is now impacting the ecosystem in the wild. This little darling produces numerous bulblets (small bulbs) that easily spread any time the soil is disturbed, so it skates across and establishes itself in the landscape with ease. It can crowd out native vegetation as its spreads, and all parts of this plant are toxic. Equally charming is the early spring native aptly named the spring beauty. The foliage and flowers are similar to the Star of Bethlehem, but spring beauties have pinstripes of enchanting pink on their petals. Spring beauty is visited by more than 20 different species of pollinators and is not toxic.

Invasive: Burning bush

Displaces native species

Native: Red chokeberry

Nutritional berries

Thick red leaves on a bush

Invasive burning bush, left, and native red chokeberry, right (Photo courtesy gailps/iNaturalist CC BY-NC, Photo courtesy Andrey Zharkikh/Flickr CC BY 2.0).

As summer brilliance gives way to the darker, muted earth tones of the autumn season, plants such as the burning bush burst into color like exploded firecrackers. People love these fiery pops of red, but like a real wildfire, the invasive burning bush has spread through the understory and taken over. It does not have many competitors here in North America and it tolerates most conditions. For a better option, look to the red chokeberry. Its fall foliage is a brilliant red, and unlike burning bush, chokeberry is still attractive throughout the rest of the year. Non-autumn foliage is a rich green, flowers are white and the nutritious red berries that appear in summer can last for months.

Invasive: European privet; Chinese privet; Border privet

Displaces native species

Native: Inkberry; Viburnum

Hosts insects and birds

White feathery flowers on a green branch

Invasive Chinese privet, left, and native arrowwood viburnum, right (Photo courtesy tnewman/iNaturalist CC BY-NC, Photo courtesy inat7/iNaturalist CC BY-NC).

Privets were originally planted as landscape hedges and have since escaped cultivation. Once on the loose, it forms dense stands by root sprouting or bird-assisted seed dispersal. Privet causes a loss of biodiversity as it crowds out native understories and forms a monotonous stretch. The effects ripple out to the insects, songbirds and other animals that depend on that biodiversity.

Many native plants can easily be adapted to hedges. The compact inkberry is a popular option, and its abundant white flowers help bees produce the sought-after gallberry honey in the southern states. Many of the viburnums can also be trained into shrubs and feature similar white flowers. Arrowwood viburnum (Viburnum dentatum) is a particularly hardy native that also sports attractive fall foliage in shades of yellow, red and purple.

Invasive: Squill

Displaces native species

Native: Virginia bluebells; Wild blue phlox

Hosts pollinators

Small plants with purple flowers

Invasive Siberian squill, left, and native wild blue phlox, right (Photo courtesy nathankiel/iNaturalist CC BY-NC, Photo by Will Parson/Chesapeake Bay Program).

“I must have planted one. Now there are thousands.” Search for scilla on any gardening site, and you’re likely to see this comment. Scilla spreads prolifically through seeds, and like lesser celandine will completely cover whatever area it invades. Once there, it crowds out the native spring ephemerals on which so many insects depend. A more ecologically friendly, native blue stunner is the Virginia bluebell. This spring ephemeral and butterfly magnet has pink buds and bell-shaped blue flowers that ring in the season nicely. If you’re partial to the delicate face of the scilla, plant instead some wild blue phlox. This delightful blue-to-purple miniature has a sweet fragrance that is most apparent on a sunny day.

What you can do

Plant-lovers are the main spreaders of, and first line of defense against, ornamental invasive plants. Learn to be an admirer of the full ecosystem by recognizing the relationships between the beautiful plants, the other flora in the environment and the insects and animals that rely on them. Pay attention to what landscapers are planting in your community, what you are planting in your own garden and what you choose to buy at nurseries. Follow the guidelines of your department of natural resources, and do your best not to plant or buy invasive species.

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Comments

Deborah Graham

Question re squill. Where I live, the 2 substitute plants you mention don't bloom till much later. Also since squill spreads by seed, how do they travel? I haven't seen birds interested and my bed of squill hasn't jumped the sidewalk in 20 years. Sweet autumn clematic though is a thug. Truly curious about squill...

Patricia Everly

have recently learned about the negative impacts of our burning bushes, I am in the process of removing them and planting Winterberry Holly , Spicebush and Arrowwood Viburnum

Terrie Lewine

Wonderful information as I continue to plan my garden!!

Chesapeake Program

These are great comments, Jeremy, thank you! Some of these issues we explore in other articles but other ones could be written about further. You might be interested in a webinar we held recently, which was all about native plants and pollinators: https://www.youtube.com/watch?v=CmREfDQ02Fk Again, thank you for the thoughtful feedback.

Jeremy Wells

I'm 100% a proponent of native plants and have spent the past three years removing invasive and non-native species from my yard (including removing a lawn) and replacing entirely with species native to our region. This is a repeat of what I did when I lived in Rhode Island. Through about 10 years of experience replacing non-natives with natives in residential landscaping, I've learned a lot that almost always is never mentioned in advocacy articles, such as this one. These issues need to be discussed in the open by proponents of native plants, such as the Chesapeake Bay Program:

1. Native plants are often much more expensive than common, non-native (and often invasive) options and, as such, is beyond the means of many people on the lower end of the socioeconomic ladder. Something as simple as replacing a lawn with native species means the difference between a $10 bag of grass seed and $1,000 of native grass plants in pots. A single star of Bethlehem bulb might cost $0.10 (or free; just wait for it to show up in your yard). A single spring beauty bulb can cost $5 to $10. This "simple" replacement can be 100 times more expensive. The growing of native plants is thus most often associated with a rather specific socioeconomic (and racial) class. How can non-profit advocacy efforts for native plants help support low-income property owners, for instance? If native plants are essential for a healthy ecosystem then why is this endeavor most often associated with wealth and White people? This is a huge issue and I wish organizations like the Chesapeake Bay Program would address it.

2. Native plants are often (and for good reason) not nearly as aggressive as non-natives. There's a reason why vinca, for instance, is so popular. You don't need to plant a lot and it spreads really quickly (quick and cheap). Most people taking the route to natives don't know this and will give up when they see how slow many natives grow and spread. Be honest about the need for patience. Non-natives are popular for a reason!

3. There is a different kind of beauty in native plants. In most cases, there really is no 1:1 visual replacement for many non-natives. Be honest about this. Natives, in general, tend to have smaller flowers, grow taller (and flop), and have more sprawling forms, compared to non-natives. Again, be honest with the public on these issues, but also introduce a more "wild" aesthetic as being acceptable, such as meadows. (Personally, I've come to prefer the meadow look and find manicured landscapes to look artificial.) Natives grow great when they have their friends to support them in a meadow planting. Non-natives have been bred for an artificially short and stout stature to fit on store shelves for sale. Thus, what people think is "normal" in a landscape is actually an aberration: Point this out in your advocacy efforts.

4. Many city and county ordinances make it difficult for people to choose native plants for their yards. Lawn mowing and anti-"weed" ordinances prejudice native plants and reward the planting of non-natives. Local government must do a better job at recognizing and rewarding the planting of natives rather than penalizing people for doing the right thing. Again, these kinds of native plant advocacy blogs never mention this important issue.

5. Most people don't know where to find native plants, especially specific species. Let people know how to find them.

6. Most nurseries will not sell plant plugs to the public (wholesale or to the trade sales only). Plant plugs can be a lot less expensive than quart or gallon pots, but many local nurseries won't/don't sell them. This is a big issue, again, in terms of cost.

7. Tell people how to plant natives from seed to save money. But, most natives don't grow particularly well from seed, so point out the natives that are most successful from this endeavor such as Coreopsis spp., many Rudbeckias, Monardas, asters, bottle brush grass, etc. Let people know about the need for cold stratification!

Again, we definitely need organizations, like the Chesapeake Bay Program, advocating for native plants in residential and commercial landscapes, but these efforts only go part way toward helping people make this change. Better education is essential.

Kathleen Killen

Thank you for sharing this great info.

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It's amazing what is all around us. I had no idea about any of these plants things for the write up! Keep the articles coming!

Jim Bogden

Thank you for the informative and useful article. Great job!

Greg DeCowsky

Adkins Arboretum, where I volunteer, switched their big spring native plant sale over to online ordering and individual scheduled pickup. This will continue for the foreseeable future. Visit adkinsarboretum.org for details.

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