Gardeners who planted creeping bellflower for its pretty lavender-blue flowers learned the hard way that this plant chokes out other flowers and proves almost impossible to eradicate. Brought originally from Europe as an ornamental, The plant is known for its bell-shaped nodding purple flowers on erect purplish stems that can grow up to 4 feet tall. It has a fast-spreading and deep root system of long tubers that grows rapidly and can take over your landscape in as little as one season if left untamed. Now that the extent of its aggressive nature has been discovered, it is classified as an invasive species. Creeping bellflower produces an abundance of seeds in the summer (upwards of 15,000 per plant), which are then easily distributed by insects and gentle breezes.
|Common Name||Creeping bellflower, rampion bellflower|
|Botanical Name||Campanula rapunculoides|
|Plant Type||Perennial, herbaceous|
|Mature Size||2–4 ft. tall, 1–3 ft. wide|
|Soil Type||Moist, well-drained|
|Flower Color||Blue, purple|
|Hardiness Zones||3–9 (USDA)|
|Native Area||Europe, Asia|
Creeping Bellflower Invasiveness
Creeping bellflower is an invasive species in most parts of North America, other than the hottest southeastern states. It was introduced during colonial times by the first European settlers.
Because creeping bellflower produces so many seeds and spreads so aggressively from rhizomes, it creates monocultures in fields, woodlands, prairies, along roadsides and streambanks, and urban wastelands. Moist and shady locations are where the plant tends to be at its most invasive but it also reseeds itself aggressively in locations with full sunlight.
What Does Creeping Bellflower Look Like
Creeping bellflower has smooth to slightly hairy stems and rough, serrate leaves. Even though there are numerous bellflower species, the creeping variety is relatively easy to identify. The leaves found at the base of the plant are heart-shaped and become narrower and more lance-like as they move upwards. The drooping, bell-shaped purple flowers appear during the summer, growing only on one side of the stem. The flowers are bell-shaped with five pointed lobes.
The plant looks very similar to native Campanula species such as harebells (Campanula rotundifolia). It also has some resemblance with native violets. To make sure that you don't accidentally remove those native plants, it is recommended that you wait for the plants to flower in order to positively identify creeping bellflower.
How to Get Rid of Creeping Bellflower
Be prepared for a long project when attempting to eradicate the tenacious creeping bellflower from your landscape. Rigorous hand pulling, mowing, and deadheading won't eradicate the species, but it'll prevent reseeding and can help control spread somewhat. It can take several years of hard work to eliminate this species, and some horticulturists choose to focus on managing it instead.
Removing The Roots
Part of the problem with removing creeping bellflower is that its white, fleshy underground rhizomes and deep taproots can't simply be pulled out. Doing so carelessly will inevitably leave pieces still in the soil, and even the smallest rhizomatous section can result in regrowth.
For the best success, digging out the roots is required. You'll need to dig at least 6 to 9 inches into the soil on all sides of the plant. Slowly and methodically sift out any root sections you find, and all parts of the plant should be put into sealed general waste bags. If added to compost heaps or bins, they could grow back once the compost is applied.
Creeping bellflower roots can also become entangled with the roots of other nearby plants. You may have to sacrifice other species while you're working to rid your garden of this weed. If you have a prized plant you want to try saving, it's best to remove it and carefully try to separate it from the roots of the bellflower. The roots should then be washed off, and the plant should be kept in a pot to make sure that no creeping bellflower growth reappears.
Another method for removing creeping bellflower is to cover the plants to deprive them of light. However, this is only practical if the flowers are growing in small patches. To do so, you can use newspapers, cardboard, or plastic, which is then covered over with soil or heavy mulch. Though it may seem easier, this method isn't always foolproof—sometimes, creeping bellflower's roots will lie in a dormant state (tricking you into thinking it's been eradicated) and new growth could appear the following season.
Chemically removing your creeping bellflower is best kept as a last resort. Not only can herbicides pose a risk to the environment, humans, and animals alike, they don't always have the best success rate. However, if you find the plant has invaded your patio. driveway cracks, or paved areas in your garden, it could be worth adopting this method as it won't be possible to dig up the roots. Likewise, if the plants have spread to your lawn, you could apply a herbicide containing the active ingredient triclopyr as this won't damage the grass.
Widely available broadleaf herbicides and defoliants such as 2,4-D have been proven ineffective at dealing with creeping bellflower. Limited success has been shown, however, with those that contain the active ingredient glyphosate (brand name: Roundup).
Treatments should be applied in late spring or early fall, while temperatures are between 60 degrees Fahrenheit and 85 degrees Fahrenheit. You also want to ensure there isn't any rain in the forecast for at least a couple of days after the treatment, too. Weekly reapplications for several weeks are often recommended.
Is creeping bellflower a native plant?
Th plant was brought to North America from its native Europe. It was initially a popular plant due to its attractive flowers and their ability to attract pollinators like bees and butterflies but it turned out to be an invasive species.
Is creeping bellflower toxic?
The plant is not toxic.
Why does creeping bellflower grow back after I dug it up?
The plant will regrow even from the smallest bit of root left in the ground. If you choose to remove it manually and without the aid of herbicides, you need to be persistent and remove any regrowth that pops up.
Creeping Bellflower. Wisconsin Master Gardeners.
Creeping Bellflower. Invasive Plant Atlas of the United States.
Safe Plants. University of California.