Nearly every flower gardener has experienced a plant that morphed from vigorous to invasive in the landscape. Sometimes self-seeding volunteers appear where they aren't wanted, and occasionally we learn the hard way why some plants have the word "weed" in their names. However, every gardener should learn about the effect imported invasive plant species have on native habitats.
Invasive plants can take over your landscape, causing the gardener to invest extra effort to control what seemed to be a low-maintenance plant. The invasive plant can spread to neighboring properties, becoming a nuisance in other gardens. Finally, even if you think your invasive plant is under control, birds could be spreading seeds to sensitive areas susceptible to aggressive species. Learn about flowers that don't mind their manners, and discover easy hybrids and wildflower replacements.
01 of 07
After all of the effort gardeners spend trying to get finicky roses to bloom and shrug off pests and diseases, an aggressive grower like Rosa multiflora seems almost welcome. However, this Asian import, which arrived in the United States in 1866 as a root stock for ornamental roses and was likely the original host plant of rose rosette disease, can now be found in large thickets in all types of habitats, from wetlands to prairies. These dense growths exclude all kinds of native plants, and disrupt the ecosystem by denying birds a place to nest. A single plant can produce one million seeds, which can retain the ability to sprout for 20 years.
If you're looking for a hardy, low-maintenance rose, plant a rose from the 'Knock Out,' 'Drift,' or 'Carefree' series. These will bloom all season with little more than annual pruning.
02 of 07
As an 1806 introduction, Japanese honeysuckle seemed like a good idea, as it was ornamental and provided erosion control. Now the plant is considered invasive across the eastern United States. The aggressive vines form smothering mats in natural areas, and can even girdle young trees. The native coral honeysuckle, Lonicera sempervirens, is a pretty substitute.
03 of 07
Weedy, destructive, and... available at your local nursery? Unfortunately, this 1916 import is still found at garden centers everywhere. Wisteria sinensis is a literal snake in the grass when it comes to forests, as the vines kill native trees by slowly strangling them, causing even mature trees to topple from girdling. This creates openings in the forest canopy that allows the invasive wisteria to proliferate even further.
Instead of Chinese wisteria, choose the native and equally lovely Wisteria frutescens. It has a less aggressive growth habit, with a mature height more suitable to gardens than its massive Asian counterpart.
04 of 07
The colorful lantana plant is popular in many gardens due to its brilliant flowers, ease of cultivation, and allure to butterflies. However, in warm climates like Florida where the shrub acts as a perennial, this ornamental is regulated as a pest plant. Lantana camara is insidious in that it vigorously displaces the already threatened native species, including L. canescens and L. depressa. An alternative plant that is even more attractive to butterflies is the native butterfly weed, Asclepias tuberosa.Continue to 5 of 7 below.
05 of 07
It's easy to see why a showy plant with an abundance of magenta wands is still in cultivation, available in many states where regulations haven't prohibited its sale. Gardeners would be wise to follow the lead of Minnesota and Illinois, which won't allow the sale or distribution of this invasive wetland plant. In marshes, along river banks, and even in ditches, this plant forms dense stands that provide no value to wildlife. Native beauties with a similar appearance include liatris for dry areas and red cardinal flower for moist gardens.
06 of 07
Brought to the United States as an ornamental plant in 1870, Spiraea japonica seemed like a benign choice in the landscape: the shrub is hardy, adaptable, and the pink flowers appeal to butterflies. However, this garden center staple has a dark side. Plants produce hundreds of seeds that germinate easily and create a dense canopy that prevents rare and threatened native spirea plants, like S. virginiana, from growing. Instead, grow sedum 'Autumn Joy,' which also sports pink flower clusters and attracts pollinators.
07 of 07
Anyone who has planted bugleweed in the hopes of covering a difficult-to-plant spot in the landscape probably won't be surprised to learn that it has invasive tendencies. After the charming purple flower spikes have faded, the plant gets busy spreading everywhere by sending out runners that rival mint in peskiness. Soon, the clump you planted beside your hosta collection is running right up the crowns of those hostas and everywhere else, taking up all of the water and nutrients and turning your garden into a monoculture. A lovely and well-behaved alternative is lungwort, which spreads slowly but not invasively in moist spots.