18 Beautiful Flowering Plants That Are Considered Invasive Species

Some non-native flowering plants are uniquely beautiful, making it tempting to keep them around the garden. They even appear to come with several benefits, like growing well in poor conditions, helping to control erosion, or attracting pollinators. However, if you take a closer look at their impact, it's easy to see how these invasive species cause more harm than good. Many of these plants grow rapidly, displacing native vegetation and greatly reducing biodiversity. A lack of diverse native species eliminates crucial food and habitat for birds, pollinators, and other wildlife, negatively affecting the entire food chain over time. 

Always double-check the name of the plants you purchase at garden centers, and keep an eye out in your yard for non-native species. Most invasives are extremely hard to get rid of, making them a nightmare to deal with in your yard and garden. While each plant is different, sometimes smothering or hand-pulling them is enough to keep them in check. For more serious infestations, it may be necessary to use chemicals to eliminate them. Whether you're worried about a mystery plant that popped up in your yard or you want to avoid accidentally purchasing an invasive species, this list will help you know what to look out for.

Also referred to as ground ivy, creeping Charlie (Glechoma hederacea) is a Eurasian native in the mint family that was introduced to North America in the 1800s. Although ground ivy grows across almost the entire U.S., it's considered invasive in several states in the Midwest, Northeast, and parts of the Southeast. This perennial weed has small, purplish blue flowers in spring and distinctive, round, scalloped leaves that smell minty when crushed.

Although it may seem like a harmless ornamental groundcover, it spreads rapidly through its seeds, rhizomes, and stolons, forming dense mats. If unmanaged, it can spread up to 7 feet in just one year. It's nearly impossible to get rid of creeping Charlie in your yard by hand because all it takes is for a tiny stem to break off for it to regrow. A three-way broadleaf herbicide will typically be your best bet to control large areas.

Japanese honeysuckle (Lonicera japonica) and other non-native honeysuckles were introduced to the U.S. in the early 1800s for their ornamental appeal and other perceived benefits. It's considered invasive across most of the Eastern U.S., from Minnesota to Maine, south through Florida, and as far west as Illinois, Kentucky, and Oregon. In New York, Florida, and several other states, it's prohibited to sell or plant. Japanese honeysuckle is recognized for its tubular, yellow or white, honeysuckle flowers in summer and its dark purple fruits in fall.

This invasive woody vine spreads by underground shoots, aboveground runners, and seeds dispersed by bird and other animal droppings. Although it thrives in full sun, it can mature and spread even in shadier environments. It also grows quickly, outcompeting native plants by climbing over them and smothering them. You can remove small patches by hand, but chemical treatments are often necessary to keep it under control.

Although Chinese wisteria (Wisteria sinensis) is commonly seen growing in the U.S., it's a non-native vine that was introduced from China in 1816. It's considered invasive in several states and is listed as a noxious weed in Wisconsin, Florida, and Maryland. While American and Asian wisterias share similar traits, the non-native varieties flower before the leaves emerge and produce fuzzy seed pods, while the native species blooms after leaf-out and has smooth pods.

Chinese wisteria is an extremely rapid grower that can be detrimental when it escapes cultivation. It smothers nearby plants and can climb high into tree canopies, often killing the trees while blocking light for lower-growing vegetation below. Even worse, it can live 50 or more years, so one plant can choke out native species for decades. If you want to get rid of wisteria, chop off the vines close to the root, then brush glyphosate directly onto the fresh cut.

Butterfly bush (Buddleja davidii) was brought to the U.S. from Asia in the early 1900s as an ornamental. This shrub is identifiable by its large clusters of bright lilac, pink, or white flowers that are highly attractive to butterflies, hence its name. Because it spreads so aggressively, it's now restricted in the Pacific Northwest and flagged as invasive in several East Coast states, including Maryland and Pennsylvania. 

It's easy to assume that because it produces nectar-rich blooms, it benefits our butterflies. However, there aren't any caterpillar species that eat butterfly bush leaves, so adult butterflies are forced to find other plants to lay their eggs on. Unfortunately, it also often crowds out the native host plants that caterpillars depend on. Each flower spike holds over 40,000 seeds that wind and water can spread over long distances, so even one plant can cause a lot of damage.

With its globe-shaped, purplish-pink flower heads, musk thistle (Carduus nutans) may look like a native thistle, but it's actually a non-native species accidentally introduced to the U.S. in the early 1900s. It's become problematic in nearly every part of the country, especially in the Midwest, Great Plains, and parts of the Northeast and Southeast, where it's considered among the highly invasive plants you should never grow.

Musk thistle can quickly take over both disturbed and open areas. Some evidence even suggests that it produces allelopathic compounds, which can make it nearly impossible for nearby plants to grow. Additionally, because livestock and wildlife avoid eating musk thistle, it can lead to overgrazing of native plants. In addition to the lack of control by grazing animals, this also allows it to dominate open areas and further reduce food for wildlife. Each plant can produce upwards of 120,000 seeds, so it can take over quickly.

You may know the Callery pear (Pyrus calleryana) by its other name, Bradford pear, which became the second most popular tree in the U.S. by the 1980s. Although initially introduced to develop a fire blight-resistant pear tree, the Bradford cultivar was also prized for its abundance of showy white flowers and brilliant fall foliage. South Carolina, Pennsylvania, and other states have banned sales of it, others are in the process of restricting it, and most of the East Coast warns against it.

Callery pear trees grow and spread rapidly, forming dense, thorny thickets that outcompete native species, and they're a scourge in urban areas. They're easily damaged in storms, produce an abundance of fruit that litters walkways, and the scent of the flowers is often compared to dead fish. Although sterile, this tree cross-pollinates with other Pyrus calleryana cultivars, producing seeds that birds disperse beyond cultivated areas.

Purple loosestrife (Lythrum salicaria) is an aquatic perennial with tall spikes of gorgeous purplish flowers. Introduced from Europe in the 1800s, this species is now considered invasive in nearly all of the Midwest, Pacific Northwest, and Northeast, and parts of the South like Texas and Florida. Although it prefers rich, moist soil, it can thrive and spread in a wide range of soils and moisture levels.

While it may look pretty, it's an extremely aggressive species that invades wetlands, displaces native plants, eliminates food and shelter for wildlife, and even chokes waterways. It offers little to no value for wildlife in these areas, as its seeds are unpalatable to birds and its dense growth is too thick for animals to use as cover. A single plant can produce up to a million tiny seeds, which then spread by wind, water, and on the bodies of passing animals.

Also known as the mimosa tree, the silk tree (Albizia julibrissin) is famous for its pink, powder-puff flowers and pretty fern-like leaves. Brought to the U.S. in 1745 as an ornamental, this Chinese native species has become a major problem in Florida's landscape. Neighboring states, reaching as far North as Pennsylvania, also strongly advise against planting this species.

Growing in a variety of soil types, this tree can grow up to 25 feet tall and can quickly take over nearly any sunny, disturbed areas, including roadsides, forests, fields, and stream banks. Silk trees spread primarily through seed, with each tree producing a mass of seed pods loaded with seeds that can stay dormant for years. When growing near waterways, the seeds can float and travel far away from the parent plant. Additionally, these trees are susceptible to mimosa wilt and other diseases and pests, have weak wood, and are easily damaged in storms.

Multiflora rose (Rosa multiflora) was initially brought to the U.S. in 1866 as rootstock, and by the 1930s, it was used for erosion control, living fences, and for its perceived benefits to wildlife. Once adored for its white flower clusters, its aggressive growth is why it's now on invasive species lists across most of the South and East Coast, along with parts of the West and Midwest. It's now classified as a noxious weed in Ohio, New Jersey, and several other states.

This invasive shrub grows rapidly, forming dense thickets that block sunlight and prevent the growth of understory plants. When its long, arching stems touch the soil, they can take root and spread in several different directions. These plants also produce up to 500,000 seeds each year that remain viable for decades, which are dispersed to new areas when birds and other animals eat the fruit.

You don't want to mistake these invasive weeds for flowers, as yellow flag iris (Iris pseudacorus) has become a major issue in our aquatic ecosystems. Although its bright yellow flowers set it apart, the foliage can look nearly identical to the native blue flag iris (Iris versicolor). It occurs in most states, many of which consider it invasive, and it's especially problematic in the Pacific Northwest, the Northeast, and parts of the Midwest.

Yellow flag iris readily escapes water gardens and spreads to new areas where it displaces native species. It forms thick, drought-tolerant rhizomes that spread through water and compete with the native plants that wildlife rely on for food and habitat. Each plant also produces several seed pods that contain 100 or more seeds and can flow downstream to colonize new areas. Wear gloves when removing this plant, as its sap can cause skin irritation.

Dame's rocket (Hesperis matronalis) is a flowering biennial with phlox-like clusters of fragrant flowers, but you don't want it in your garden. Although it may look like a wildflower, it was introduced by European settlers in the 1600s. It has since become recognized as an invasive species in much of the northern half of the United States and into Canada. Colorado, Wisconsin, and other states have it listed as a noxious weed.

One of the biggest issues with Dame's rocket is that it's sometimes added to "wildflower" seed mixes, so it's important to always double-check the species list, even on packets labeled as native. Mature plants can produce hundreds of seedpods that burst and scatter seeds that can stay viable for years. As they turn into mature plants, they form thick stands that crowd out native wildflowers and reduce biodiversity in woodlands and other areas.

Although it's readily available in many garden centers, you'll want to be cautious before planting perwinkle (Vinca minor). It's often advertised as a fast-spreading, low-growing ground cover that blankets your yard with pretty purple flowers, but it's often more trouble than it's worth. This plant has escaped cultivation and now occurs throughout the country, particularly in the Eastern U.S. There aren't any states that have flat-out banned this perennial, though several regions urge gardeners to consider alternatives.

A small periwinkle plant can grow vigorously, outcompeting nearly any plant in its path, including valuable wildflowers. Not only does it spread by underground runners, but it can also root at stem nodes that come in contact with the soil. Because of this, all it takes is a tiny fragment left behind for a new plant to pop up in its place, making it challenging to eliminate.

Amur honeysuckle (Lonicera maackii) may put out flowers that attract hummingbirds, but it's not a honeysuckle you want to see in your yard. This species has fragrant, white, tubular blooms that emerge in spring, followed by bright red berries. Introduced to the U.S. in 1898, this shrub has since become an issue throughout much of the South, Midwest, and Eastern states, which is why it's prohibited in Illinois and other areas. 

Birds and small animals snack on the berries, scattering seeds in new areas. A mature plant can produce up to a million seeds, allowing amur honeysuckle to spread uncontrollably and form impenetrable stands that smother out native vegetation. Not only does this reduce biodiversity, but it also leaves wildlife with lower-quality fruits compared to native species. Additionally, its leaves emerge earlier in the season, giving it another competitive edge.

Crown vetch arrived in the U.S. as early as the mid-1800s, though its popularity peaked in the 1950s as a soil stabilizer and ground cover. It has since spread into nearly every state across the country, causing it to land on invasive lists in several Midwest, Southern, and Eastern states. This perennial legume is also banned in Wisconsin and Minnesota, where it's classified as a noxious weed.

Spreading by both seeds and rhizomes, a single crown vetch plant can cover up to 100 square feet within a few years. The rhizomes can achieve major spread, producing up to 10 feet of horizontal growth and sending up shoots to produce new plants. Wildlife can also drop the seeds into new areas. Unfortunately, it doesn't take long for this plant to displace an array of native plants, reducing biodiversity and wildlife habitat.

Native to Japan and China, sweet autumn clematis (Clematis terniflora) is a vine that was once prized for its clusters of starry, white, fragrant flowers. It's another species that is taking over the eastern U.S., covering as far west as Minnesota and south as Texas and Florida. Several states warn against planting this invasive species, including Florida, Georgia, Alabama, Illinois, Delaware, New Jersey, and the Carolinas.

Sweet autumn clematis readily self-seeds, producing thousands of feathery seeds each year. As wind, water, or animals carry them, they can easily wind up on roadsides, stream edges, along forests, and in many other areas. This perennial vine grows rapidly, reaching up to 30 feet. Its vines climb over native shrubs, trees, and other plants, creating dense growth that blocks sunlight from the natives beneath. The best way to treat it is to cut it back and apply an herbicide.

Although Mexican petunia is a stunning purple flower that thrives in late summer heat, you should grow it with caution. It was introduced to the U.S. in the early 1900s, and has since naturalized in eight eastern states. Because it has naturalized in dozens of Florida counties, the Florida Exotic Pest Plant Council (FLEPPC) declared it a Category I invasive species in 2001. Although there are sterile cultivars, they look strikingly similar to their problematic counterpart, so it's still not recommended for planting.

This herbaceous perennial aggressively self-seeds and spreads through underground runners, so it's likely to escape the garden and wind up in other natural areas far from where you've planted it. Plus, the seeds and rhizomes can float on water. Even tiny pieces of a rhizome can regrow into a new plant, so it's extremely hard to get rid of.

Japanese spirea (Spiraea japonica) is a small flowering shrub with pretty pink flower clusters in summer. Native to eastern Asia, this shrub was brought to America around 1879 and became a popular landscape plant for its showy blooms. It has since escaped cultivation and has now naturalized throughout the Midwest and the Eastern U.S. Many states have reported its invasiveness, including Maryland, Kentucky, Tennessee, and Virginia. 

Like many fast-spreading non-natives, Japanese spiraea wipes out native species, which leads to less food and habitat for wildlife. Each plant produces hundreds of seeds that can stay viable in the soil for long periods of time. The seeds often travel down streams or other moving bodies of water, though they can also be transported in fill dirt. Unfortunately, this hardy non-native will invade and thrive in several soil types and habitats, like fields, forests, and along streams, rivers, or roadsides.

Lantanas are a group of flowering shrubs that are famous for their clusters of multicolored blooms that attract butterflies. The native species are beneficial for local pollinators. The non-native Lantana strigocamara, sometimes called Lantana camara,  attracts hummingbirds, but poses a serious issue in Florida, where it's considered invasive and isn't recommended for planting in any part of the state.

One surprising reason Lantana strigocamera is so detrimental to the ecosystem is its ability to alter the soil chemistry, creating an environment where non-natives thrive and native plants struggle. Its dense growth crowds out native species and casts shade on low-growing species. It can also hybridize with endangered native lantana, contaminating the gene pool. Although some sterile varieties are said to be less threatening, you'll want to remove the plant immediately if you see it producing its tiny black seeds.