Nettle-leaved bellflower (Campanula trachelium) is a small flower found in Europe and Africa. It grows in woodlands, hedgerows, and the edges of forests. In landscaping, it is used most commonly for naturalistic borders due to its height and lovely summer blooms.
I. Appearance and Characteristics
Campanula trachelium, the nettle-leaved bellflower, is a species of bellflower. It is a Eurasian blue wildflower native to Denmark and England and now naturalized in southeast Ireland. It is also found southward through much of Europe into Africa.
The alternate name throatwort is derived from an old belief that C. trachelium is a cure for sore throat, and the species name trachelium refers to its use as treatment of the throat in folk medicine.
Other folknames include Our Lady’s Bells because the color blue was identified with the Virgin Mary’s scarf, veil, or shawl; Coventry Bells because C. trachelium was especially common in fields around Coventry; and “Bats-in-the-Belfry” or in the singular “Bat-in-the-Belfry”, because the stamens inside the flower were like bats hanging in the bell of a church steeple.
Campanula trachelium is a perennial plant with one or more unbranched, often reddish, square-edged stems that are roughly hairy. The leaves grow alternately up the stems. The lower leaves are long-stalked and ovate with a heart-shaped base. The upper leaves have no stalks and are ovate or lanceolate, hairy with toothed margins.
The inflorescence is a one sided spike with a few slightly nodding flowers. Each flower has five sepals which are fused, erect and hairy, and the five violet (or occasionally white) petals are fused into a bell that is hairy inside. There are five stamens and a pistil formed from three fused carpels. The fruit is a hairy, nodding capsule.
Campanula trachelium likes humus-rich soil and is found in broad-leaved woodlands, coppices, hedgerows and the margins of forests.
II. How to Grow and Care
Sunlight
Nettle-leaved bellflower thrives in partial sun, where it receives bright but indirect light for optimal growth. It tolerates full sun conditions; however, in much harsher sunlight, nettle-leaved bellflower’s growth and health can be compromised. Excessive direct light can lead to leaf scorch or faded foliage, whereas in its ideal setting, nettle-leaved bellflower exhibits rich, green leaves and robust bloomings. Outdoors, nettle-leaved bellflower should be planted in a location that provides filtered sunlight, such as under the light canopy of larger plants, to ensure it receives the gentle light it prefers. This balance of light ensures the healthiest growth of nettle-leaved bellflower, fostering its delicate, bell-shaped flowers and robust perennial nature.
Temperature
Native to northern temperate regions, the nettle-leaved bellflower is suited to USDA hardiness zones 4-8. The plant thrives in temperatures around 16 to 18 ℃, and some varieties will survive cold temperatures down to -10 ℃. Although they prefer a cool summer, the nettle-leaved bellflower can survive in temperatures up to 26 ℃, as long as they are regularly watered. If the temperature exceeds this, then the flowers will die, and the plant may not bloom again that year.
The nettle-leaved bellflower is a flowering plant that adds a whimsical feel to many gardens across the world. Depending on the climate, it will generally bloom from the beginning of summer through to the first frost. While they are reasonably easy to care for, you will need to regularly check that they have enough water in order to prevent the delicate flowers from wilting.
Watering
Thriving in its native woodland settings, nettle-leaved bellflower has adapted to moderate moisture levels and partial shade. It exhibits a preference for consistent soil moisture without being waterlogged, reflecting its balance between drought tolerance and humidity appreciation. Regular watering every week supports its health and vigor. Ideally suited for outdoor cultivation due to its resilience, nettle-leaved bellflower flourishes when the soil’s moisture is closely monitored during its active growing season, ensuring optimal growth without excess water stress.
Soil
The optimum soil for your nettle-leaved bellflower is fertile soil with a pH of 6-8, meaning neutral to alkaline. The soil must not dry too quickly, but should still be well-draining. Because of this, soils such as loam, sand, or clay are perfect for this plant. The nettle-leaved bellflower does not like warm weather, so apply a layer of mulch to the soil in the summer. This will help to keep the soil and the roots of your plant cool and moist. The nutrients from the mulch will also encourage better growth and blooming.
Fertilizing
For nettle-leaved bellflower, optimal fertilization involves using balanced nutrition fertilizers, applied quarterly at the start of each growth season. Fertilizing promotes robust growth and vibrant blooms, enhancing nettle-leaved bellflower’s vigor. Use a light hand with the fertilizer dose to prevent root burn. Adjust feeding with the seasons, less in winter. Always water soil before fertilizing to protect nettle-leaved bellflower’s roots.
Pruning
The typical nettle-leaved bellflower will usually grow up to 1 m and reach an ultimate spread of 1 m. They are perennial, which means that they will bloom once a year. Because of this, they do not necessarily need pruning, unless you are trying to maintain a certain shape. The nettle-leaved bellflower can take up to 5 years to reach its ultimate height, which is another reason why you may not need to prune your plant for quite a few years.
If you choose to prune for shape and to encourage growth, you should do this at the end of spring, and definitely before the beginning of fall. While pruning, remove any shoots that appear weak or are growing in the wrong direction. This will encourage the plant’s energy to be diverted towards the other shoots instead. During the flowering season, some choose to remove wilted flowers, as this can prolong the flowering phase. This can be done by ‘plucking’ off the dead flowers. Deadheading flowers will also prevent this plant from self-seeding.
Propagation
Nettle-leaved bellflower can be propagated successfully through cuttings, a method capitalizing on its natural ability to generate new roots. Take semi-ripe cuttings from healthy plants during the active growing phase, ensuring each piece has several nodes. Plant the cuttings in a well-draining, nutrient-rich medium, maintaining steady moisture without waterlogging. Rooted cuttings should be hardened off before transplanting to their final position to ensure acclimatization and robust growth.
Transplanting
For optimal results, transplant nettle-leaved bellflower in the S1-S2 season, or more gracefully put, during the cocoon of early spring to heart of summer. This ensures root development before winter. A semi-shaded spot with moist but well-drained soil suits best. Remember, avoid excessive sunlight exposure for nettle-leaved bellflower.
III. Uses and Benefits
Consider planting nettle-leaved bellflower in garden borders, wildflower gardens, and low-maintenance gardens. When grown in groups, the nodding, tubular, blue or lilac blossoms provide attractive color in the landscape from late summer to early fall.