Dalmatian bellflowers (Campanula portenschlagiana) are low-growing herbaceous perennial flowers that are often used as edging plants in perennial borders, to spill over stone retaining walls, or to fill in gaps between stepping stones. Like other members of the very large Campanula genus, dalmatian bellflowers have dark green leaves and purple or blue cup- or bell-shaped flowers. This plant usually blooms from late spring nearly into fall. In many climates, they are virtually evergreen, since new leaves are constantly replacing old leaves as the mature leaves fade and turn brown.
Campanula portenschlagiana (formerly known as C. muralis)
|Common Name||Dalmatian bellflower, Adria bellflower, wall bellflower|
|Plant Type||Herbaceous perennial flower|
|Mature Size||3 to 6 inches tall; 6- to 12-inch spread wide|
|Sun Exposure||Full sun to part shade|
|Soil Type||Medium moisture, well-drained soil|
|Soil pH||6.6 to 8.5 (neutral to alkaline)|
|Flower Color||Violet, blue|
|Hardiness Zones||4 to 8 (USDA)|
|Native Area||Dalmation mountains of Croatia and Herzegovina|
How to Grow Dalmation Bellflower
Because Dalmation bellflower has weak stems and an ability to spread via rhizomes, the most natural use of this perennial is as a ground cover. Alternatively, you can train them to grow upward, using a peony ring or similar support structure. Dalmatian bellflowers should be planted in average well-drained soil that remains consistently damp but not soggy. They generally like full sun, but in warmer climates, they will perform better if given some shade.
In ideal conditions, this plant will spread fairly quickly, both by extending its rhizomatous roots and by self-seeding. Dalmation bellflowers are sturdy plants that have few serious insect pests or diseases, but slugs and snails often enjoy feasting on the leaves.
Growing From Seeds
Dalmation bellflowers are good candidates for seed germination to get a head start on the season. Plant the seeds in flats (or as desired). Press the seeds into the soil without covering them. Provide light to promote germination, and maintain a temperature of 70 degrees Fahrenheit for two to four weeks. Transplant the seedlings with approximately 6- to 12-inch spacing.
This plant thrives in full sun to part shade; the hotter the climate, the more it will appreciate some shade. This species tolerates more shade than most other Campanula plants.
This plant prefers moist but well-drained soil but does fairly well in average soil types without much organic material.
Dalmatian bellflowers have typical needs for water. About 1 inch of water per week, in the form of rainfall or irrigation, will keep them blooming. Once well established, Dalmatian bellflowers can tolerate short periods of drought.
Temperature and Humidity
These plants perform poorly in climates with hot, humid conditions where night temperatures remain above 70 degrees Fahrenheit. They do well wherever conditions are cooler than this in zones 4 to 8.
This is a hardy plant that doesn't require much feeding. A spring application of organic fertilizer or a layer of compost will provide all nutrients necessary.
Dalmation bellflowers are herbaceous plants that do not need pruning in the way that trees and woody shrubs do, but pruning or trimming the plants can help promote flowering in summer. Cutting back the dead foliage in fall gets the plant ready for the cold winter ahead.
If your bellflower's blooming tapers off as the summer progresses, sheer the plants to induce additional flowering. In addition, regular deadheading of spent flowers during the growing season will also help prolong the bloom periods.
To prepare the plants for winter, wait until the first frost or two has killed the foliage (do not prune live foliage), then cut back the plants to the ground. Cover the soil around the plants with an inch or two of compost, then add a layer of straw or mulch material to keep out weed seeds. Remove the mulch in spring.
Propagating Dalmatian Bellflowers
Dalmatian bellflowers will readily self-seed, and the offspring plants can be carefully dug up and transplanted to other locations. It is also quite easy to propagate bellflowers by dividing them. Simply cut away a portion of the plant clump at the perimeter, making sure to get both foliage and a section of roots, then transplant the section immediately to a new location. Make sure the roots are fully buried.
Varieties and Related Species
- Campanula portenschlagiana 'Aurea': One of the most popular cultivars, commonly called golden dalmatian bellflower; attractive golden spring foliage that gradually acquires green tones as the growing season progresses
- C. portenschlagiana ‘Birch’s Hybrid’: A more upright plant with true blue flowers, with tinges of purple at the margins
- C. portenschlagiana ‘Resholdt's Variety’: A slightly larger variety, growing to 12 inches high, with lilac blooms
- Campanula poscharskyana: A different but similar species to C. portenschlagiana; grows to 12 inches in height; common name is Serbian bellflower
- C. carpatica: Another similar species; mound-forming bellflower that grows 12 inches tall and is available in white cultivars; not a creeping spreader but can be frequently divided and replanted to cover large areas of ground; common names are Carpathian bellflower and tussock bellflower