While beautiful, purple loosestrife, known as the “purple plague,” (Lythrum salicaria) is an ornamental plant known for its purple-spiked flowers. Purple loosestrife was brought to New England as an ornamental plant in the early 1800s. Once limited to gardens in the Northeast, it now chokes wetlands across the country.
Purple loosestrife has the ability to produce millions of seeds which spread easily by wind or water. Stands grow to thousands of acres in size, eliminating crucial open-water habitat for species such as butterflies and rare amphibians, and ultimately change an entire ecosystem. Efforts to control purple loosestrife cost the U.S. economy an estimated $45 million each year. Purple loosestrife lacks a natural predator, such as a beetle that feeds on its roots and leaves, in the U.S.
If you find it growing on your property, simply pulling it up or using herbicides can work to remove it. Once a large population is established, however, it is extremely difficult to remove.
An alternative to Purple Loosestrife is Blazing Star, which has spiked, pink-purple flowers and is an important source of nectar for many native species of butterflies and other insects or consult your local nursery for other alternatives.
Another invasive plant:
I myself only discovered this while doing the post on the purple loosestrife:
Dames Rocket, above, is classified as an noxious weed. Some, including myself, may incorrectly call it wild Phlox, but Dame’s Rocket (Hesperis matronalis) is a Eurasian biennial belonging to the mustard family. It was introduced to North America in the 1600’s and has naturalized itself in moist, wooded areas, but can also invade open areas. It may be sold in garden centers as a perennial and is often included in “wildflower” seed mixes. The plant’s 3-month-long blooming period and ability to set abundant seed have contributed to its spread.
Dames Rocket has 4 petals per flower, whereas Phlox has 5 petals per flower. I have cut these wildflowers and brought them home to enjoy thinking they were wild phlox. I'll just purchase the real phlox from the nursery and will enjoy the real deal instead of transplanting dames rocket.
Visit Susan at A Southern Daydreamer to view Outdoor Wednesday for other outdoor posts.