How to Grow Creeping Bellflower

Creeping bellflower plant with drooping bell-shaped purple flowers on thin stems

The Spruce / Evgeniya Vlasova

Creeping bellflower is a delicate, hardy, disease-resistant perennial that grows readily in a variety of conditions. 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 up one side of the stem. You may think that a beautiful, easy-to-grow plant would make for a perfect garden bloom, but you'd be wrong—in fact, creeping bellflower is considered extremely invasive.

If you introduce this aggressive species to your garden, you must do so carefully and strategically—otherwise, it won't be long before it chokes out your other flowers and proves almost impossible to eradicate. It has a fast-spreading and deep root system of long tubers that can become many gardeners' nemesis if left untamed. Now that the extent of its aggressive nature has been discovered, it's classed as an invasive species across much of the country.

Brought to North America from its native Europe, creeping bellflower was initially a popular plant thanks to its ability to attract pollinators like bees and butterflies. 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. The plant will grow rapidly and can take over your landscape in as little as a season if left to its own devices. Ultimately, though it is beautiful, it's not recommended that you plant creeping bellflower in your garden or landscape.

Botanical Name Campanula rapunculoides
Common Name Creeping bellflower, rampion bellflower
Plant Type Herbaceous perennial
Mature Size 2–4 ft. tall, 1–3 ft. wide
Sun Exposure Full sun, partial shade
Soil Type Moist but well-drained
Soil pH Neutral to acidic
Bloom Time July to September
Flower Color Lavender, purple
Hardiness Zones 3–9 (USDA)
Native Area Europe

Creeping Bellflower Care

Creeping bellflower grows pretty much anywhere. It can thrive in various light conditions and handles a variety of different soil types easily—even those that have poor drainage or are infertile. It's found in most parts of North America, other than the hottest southeastern states. That being said, moist and shady locations are where the plant tends to be at its most invasive.

Creeping bellflower weed plant with long thin stems and purple bell-shaped flowers in garden

The Spruce / Evgeniya Vlasova

Creeping bellflower weed plant with purple bell-shaped flowers on stems closeup

The Spruce / Evgeniya Vlasova

Light

Creeping bellflower will be most pervasive (and reseeds itself most aggressively) when growing in full sunlight. However, the plant can sustain just fine in partial shade and full shade locations as well.

Soil

While it can tolerate a variety of soil conditions, creeping bellflower will grow most prolifically in a soil blend that is moist but well-draining. Additionally, it can adapt to a wide range of neutral to acidic pH levels.

Water

Creeping bellflower plants prefer consistent water, and do best with about 1 inch of water per week, either from rainfall or manual watering methods. Once established, they are mildly drought-tolerant, though a lack of water will impact their blooming.

Temperature and Humidity

Though creeping bellflower is well-adapted to a variety of temperature and humidity environments, it spreads and grows most rapidly in the cooler weather of early spring or late fall. Additionally, the plants are cold-hardy down to about 5 degrees Fahrenheit, though they will cease to bloom at extremely cold temperatures.

Fertilizer

Creeping bellflower spreads readily and aggressively on its own, and should not be given fertilizer.

How to Remove 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.

Smothering Methods

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.

Chemical Removal

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, but 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, likeRoundup. Applying the treatment directly with a sponge can prevent it from coming into contact with other nearby broadleaf species. Best success, however, will occur if it's sprayed generously on the plant.

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.