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Cedar Rapids, Iowa 52401
The Iowa Gardener: Not all bellflowers are created equal
Creeping bellflower is an invasive plant that will take over a garden
“Tear it out. Right now.”
A talented Master Gardener friend was visiting my garden and spotted a tiny little cluster of heart-shaped leaves. Looking at it, I thought maybe it was a wild violet.
“Everyone keeps it at first because it’s so pretty. But I promise you it’s the devil.”
That was 20 years ago, and he was right. Creeping bellflower, Campanula rapunculoides, is also known as wild campanula, rampion bellflower, creeping bluebell, and many others. It is one of the worst and most persistent weeds in my garden. Unlike creeping charlie, another contender in my garden for Worst Weed Ever, creeping bellflower is not easy to remove. It tends to pack itself in among the stems of other plants and has delicate little stems and roots that are hard to get out completely.
If you are seduced by its charms and don’t control it, it will take over whole portions of flower beds and lawns, choking out the flowers, vegetables, or grass you are trying to grow.
Where did it come from?
Some stories have creeping bellflower originating in Asia and being sold for many years in the United States as a garden plant. Others assert that it was brought with colonial Europeans to New England in the 17th century. Wikipedia says it’s a native of southern Europe and East Asia.
The foliage grows 1 feet to 3 feet tall, with flower spikes that produce rows of lovely lavender bell-shaped flowers hanging from them in early summer. The medium green leaves stay attractive all growing season long. It is drought-tolerant. It thrives in wet conditions. It does well in both sun and shade — which all would be great if it weren’t such a horticultural bully.
Creeping bellflower, the nasty weed, should not be confused with other bellflowers. There are many different sorts of campanulas sold in garden centers that have the same or even prettier white, pink, or blue bell-shaped flowers hanging from flower spikes. I have a couple in my garden, and the irony is not lost in me when I weed out the wild campanula from among my beautiful and better-behaved purchased campanulas.
Creeping bellflower also should not be confused with our own native bellflower, which is much better-behaved. Campanula americana tends to grow taller, up to six foot, and the flowers looks similar but are more flat. It also isn’t invasive like creeping bellflower.
How to manage it
Wild campanulas are so tricky because of their roots. The have fine little roots near the surface, attached delicately to the slender stems. But they also have thicker, more substantial roots known as tubers deeper down and it’s almost impossible to get those as well. I can pull and dig — as best I can — a whole patch of campanulas but they often come back seemingly overnight.
It’s almost impossible to get rid of creeping bellflower completely, but you can manage it. Here’s how.
- In early spring, pull and/or dig up as much as you can, going down about 6 inches if possible to get all the roots.
- Creeping bellflower tends to intertwine itself with other more desirable perennials. In my garden, for example, it’s hardest to get it out from my German bearded irises and peonies. If other methods don’t work, you may have to dig up those plants along with the campanula. Then carefully pick out the weed and then replant the desirable plants.
- If you choose to use chemicals, glyphosate (Roundup is one brand name) works on creeping bellflower. However, glyphosate damages whatever plants it touches, so it’s tricky to use in among other plantings. Also, creeping bellflower is so resilient that it usually takes repeat applications to completely kill it.
- Mulch helps. A thick cover of mulch (at least 1 inch and up to 3 inches) applied in late spring will suffocate emerging creeping bellflower. A bonus is that mulch will suppress other weeds as well, conserves moisture, and prevents a number of plant diseases.
Veronica Lorson Fowler is co-publisher of the Iowa Gardener website at www.theiowagardener.com.
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