I received a comment from Susanne Davis who lives in New York, “I know every perennial’s job is to spread and ‘take over.’ I have battled all kinds of plants who have done their job better than I wanted them to do. However, this plant makes all the rest seem like slackers. This plant has choked out everything in its wake in several places in my huge cottage garden. Last summer was so hot and dry, I know I did neglect the gardens somewhat, but this spring, this plant created an emergency situation.
“Truly. I only garden organically, so I am spending day after day digging in my clay soil and re-planting the plants that are being choked out. I just spent my fourth eight-hour day, and I am not even half done. My husband worked for three hours today, and an experienced gardening friend spent three hours. I may need to hire help. Its leaves are absolutely everywhere. My back aches, and I am so very sorry I bought this plant not that long ago. I feel better knowing I am not alone.”
Creeping bellflower or European bellflower (Campanula rapunculoides) is a highly invasive flowering species. Ready-to-apply RoundUp is ineffective. Digging it out is relatively ineffective as well, since any little fragment of its taproot left behind will sprout a new plant. I have smothered clumps in my prairie with some success.
Creeping bellflower blooms look similar to the native harebell or bluebell bellflower (Campanula rotundifolia). But, unlike the native species, the 5-petaled, violet-blue bell-shaped flowers alternate up one side of its sturdy 3-4′ stem, and it produces new plants from its roots as it creeps along underground. Its serrated leaves have a broad base that narrows to a tip, and they seem to stay green all year long. It also reproduces by seed, so there’s a double-whammy in trying to keep it under control.
The much more delicate-looking native bellflower’s violet-blue blooms, on the other hand, loosely cluster at the ends of the stems, often causing the plant to nod from the weight. The round basal leaves wither early, leaving only stems and blooms near the end of season. The native bluebell bellflower or harebell remains a single plant and reproduces only by seed.
This biennial plant likes moist areas such as woods and wetlands. Its blue blossoms are more wheel-shaped than bell-shaped, and cluster along all sides of its hairy stem. It has a long, curving style, which protrudes from the creamy-white center ring.
When purchasing or accepting plants, watch out for these! But as it often goes, along with the plants we want in our gardens, come plants we don’t want. They are currently listed under Wisconsin’s NR 40 Rule as regulated terrestrial invasive species.