How to Plant and Grow Bellflower

Bellflowers are a diverse, easy-to-grow group of plants that come in many sizes and varieties, perfect for a low-maintenance cottage garden. From diminutive alpine species to upright woodland varieties that make pretty cut flowers, most types of bellflowers feature the trademark bell-shaped blossoms, comprised of five petals fused at the base. Depending on the variety, these bells sometimes face upward on little mats of foliage, or they may dangle in the breeze, suspended in drooping clusters. No matter how they’re held, the display of blooms will always be abundant.

Bellflowers are among the most popular blue flowers, a rare hue in the plant world. While blue is the most common color, you can also find them in purple, white, and pink. These cheery little bells will grace your garden for weeks, generally starting in late spring and continuing through summer.

Where to Plant Bellflower

Because this is such a diverse group of plants, it’s always best to research and read labels on specific varieties before planting them in your garden. Bellflowers are native to so many different geographic areas that what works for one type may not be ideal for another. With that in mind, there are some general tips for meeting bellflower care needs.

When looking for a place to plant your bellflowers, know that most species prefer well-drained soil. A few exceptions can handle moist soils and, in some cases, persistent wetness. However, many smaller alpine species prefer the opposite and like to grow in sharply drained soil. These types may even grow in rock walls, trough gardens, and other less-than-ideal places.

Most bellflowers will perform best in full sun. A few woodland species grow well in part shade and full shade, but for the best flower display, you should generally grow bellflowers in full sun. Sunshine also helps prevent taller varieties from flopping and needing stakes.

How and When to Plant Bellflowers

Plan to plant your bellflowers in the spring, once you’re confident the last frost has occurred. Some varieties can also be planted in the fall. Choose an overcast day or wait until the late afternoon when the sun is less intense to prevent transplant shock. Prepare the soil by turning it under, roughly 6 to 12 inches, and remove any debris; add compost or manure if needed.

Dig a hole slightly larger than the bellflower’s root ball, aligning the top of the roots with the ground. After filling in the hole, tamp down the soil with your hand. Give the plant a generous drink, then add a layer of mulch around it to conserve moisture.

Bellflower Care Tips

These flowering beauties are generally low-maintenance and don’t often have major pest problems, making them a great choice for a beginner gardener.

Light

For many types of bellflower, full sun is best, although some woodland species perform well in part shade or even full shade. For taller types, sunshine is essential for keeping the flowers standing tall, so you don’t have to worry about staking them. Read the label of the variety you purchase for more specific care instructions.

Soil and Water

Most often, you’ll want to seek well-drained soil when planting bellflowers. However, some types will tolerate moist, even occasionally wet, soil. Many alpine species, such as Campanula saxifraga, require very well-drained soil, making them capable of growing on rock walls or in other challenging spots. Soil pH requirements vary from species to species, though most tend to perform well in neutral soil.

While you should follow the care instructions on your plant’s label, there are some general watering guidelines. After planting, water your bellflower at least once a week, keeping the soil damp about an inch below the surface. Early morning is the best time to give your bellflower a drink. That way, the leaves can dry off as the temperature rises.

Temperature and Humidity

For most varieties, warm days and cool nights yield the best growth. Some species won’t survive long if nighttime temperatures stay above 70℉ and conditions are humid. In regions where daytime temperatures are high, certain types may do better in partial sun, rather than full sun.

Fertilizer

If you notice new growth on your bellflower, it may benefit from a light application of fertilizer. When using granular formulations, avoid the leaves and crown to protect the plant from burns. Slow-release fertilizers should be used sparingly, because these can promote root rot in bellflowers.

Pruning

Deadheading, or removing spent blossoms, can encourage some species to produce more flowers. This can be a slow process, as you should remove each blossom individually to avoid accidentally taking off new buds on the same stalk. Make sure to do your research: Some varieties shouldn’t be deadheaded after the first flush, since new flowers will soon follow. As summer progresses, you may want to trim off any foliage that is past its prime.

Pests and Problems

Bellflowers aren’t usually pest-prone, though they may occasionally have issues with aphids, snails, slugs, spider mites, thrips, or whiteflies.

Rust may appear as light-colored leaf spots and red-orange pustules on the underside of leaves. This is more likely to occur when conditions are damp. Water bellflowers at the base to reduce the risk of this disease, and remove any infected sections, destroying them so the disease can’t spread.

Powdery mildew, which looks like white or gray powder on leaves, is a fungal disease that may affect bellflowers. Eventually, infected foliage may turn brown and shrivel up. If you notice diseased leaves, pluck and destroy them. Proper spacing can reduce the risk of this problem.

How to Propagate Bellflowers

Depending on the type of bellflower, you can propagate your plants from seed, division, and stem cuttings.

Seed

Some bellflowers reseed on their own. However, if you are starting new plants from seed, note that they won’t produce blossoms until the second growing season. About 8 to 10 weeks before your spring planting date, sow the seeds in a tray and cover them with seed-starting mix. Keep the soil moist and warm, between 65℉ and 70℉. Expect seedlings to emerge within 20 to 30 days. Move them to a sunny location until they’re 3 to 4 inches tall. After 3 to 4 weeks, apply fertilizer according to package directions.

Place the seedlings outdoors once they have four leaves, but don’t plant them right away. First they need to be hardened off, which means slowly acclimated to outdoor conditions. Place the tray in a protected area shielded from wind and heat. If frost is a possibility, bring the tray back indoors for the night. After a week, you can plant your seedlings in the ground.

You can also directly sow bellflower seeds outside after the risk of frost has passed. Add organic matter to the soil, then evenly distribute the seeds, covering them only lightly with soil. Water regularly to keep the soil moist. Note: Some types of bellflower seeds need to be cold-stratified, requiring you to plant them outside in the winter.

Division

There’s no strict schedule for dividing bellflowers—simply do it as needed, maybe every two to five years, depending on the type. This can help stop the plant from spreading indiscriminately. Division is typically done in the fall, about four to six weeks before the first frost, though some species of bellflower do better if divided in spring or summer.

The day before you divide, give the plant a good watering; perform the division at a time of day when the plant is in the shade. As you carefully dig up your bellflower, make sure you extract all of the roots. Pull or cut the clump apart into a few sections, making sure each has roots and new growth. Transplant the divided plants as quickly as possible.

Stem Cuttings

Bellflowers have soft stems rather than woody ones, so cuttings can be taken from the young growth of the plant. Many species bloom in the summer, so cuttings should be taken in the spring. For spring bloomers, take cuttings in summer or early fall. Cut about 4 inches from the end of the stem right underneath a node. Remove the lower leaves from the stem, dip it into growth hormone, then poke the stem into a pot of growing medium. (You can use a pencil to pre-poke a hole.) After covering the pot in plastic, place it in a warm, well-lit spot.

Editor’s Note: This method isn’t recommended for all varieties of bellflower, so research your particular cultivar before propagating.

Types of Bellflower

‘Birch Hybrid’ Bellflower

‘Birch Hybrid’ is a groundcover that bears 1-inch-long fluted lavender-blue flowers from late spring through late summer (if deadheaded). It makes a great rock garden plant. This variety is hardy in Zones 4–7.

Campanula Raddeana

Campanula raddeana grows to a foot tall and produces 1-inch-diameter, bell-shape flowers in the midsummer. It is hardy in Zones 5–8.

Clustered Bellflower

Campanula glomerata sports tight clusters of purple blooms on 2-foot-tall stalks in early summer. It quickly spreads to form a large mat. It is hardy in Zones 3–8 and can be invasive, especially if you have moist soil.

Peach-Leaf Bellflower

Campanula persicifolia grows a foot tall and wide with fine foliage. In early summer, it sends up wiry stems with violet, blue-violet, pink, or white flowers. It is hardy in Zones 3–8.

‘Pearl Light Blue’ Carpathian Bellflower

Campanula carpatica ‘Pearl Light Blue’ features 2-inch-wide, cup-shape flowers that are light blue with a white center. It reblooms all summer if deadheaded regularly. This cultivar is hardy in Zones 4–7.

‘Pink Octopus’ Bellflower

Campanula ‘Pink Octopus’ has unique flowers with straplike pink petals that look like creatures from the depths of the sea or outer space. The blossoms rise a foot above the foliage on plants that spread to 18 inches wide. It is hardy in Zones 5–8

‘Sarastro’ Bellflower

Campanula ‘Sarastro’ is covered in long, bell-shaped, deep purple flowers on 18-inch-tall stems in early summer. It reblooms throughout the summer if faded flower stalks are removed. This cultivar spreads to form a large clump and is hardy in Zones 4–8.

White Canterbury Bells

Campanula medium ‘Alba’ is a biennial that produces dramatic 3-foot-tall white flower spires. It is hardy in Zones 5–8.

White Peach-Leaf Bellflower

Campanula persicifolia ‘Alba’ bears pure-white flowers in summer. It grows 3 feet tall and wide and is hardy in Zones 3–8.

Bellflower Companion Plants

Foxglove

The tall spires of foxglove, rising in the garden in early summer, are a sight to behold. Most types are biennials—they need two years to bloom, then die in the fall. But if you can nurture a thriving stand of foxgloves, they’ll reseed so prolifically it will seem they’re perennials.

For successful growth, foxgloves must have rich, moist, well-drained soil and light shade, especially in the afternoon. (They’ll do fine in full sun in the northern third of the country.) These tall plants also need to be out of any wind. Plants may rebloom if deadheaded after the first flush of bloom.

Phlox

Phlox are one of those bounteous summer flowers that any large, sunny flowerbed or border shouldn’t be without. There are several different kinds of phlox: Garden and meadow phlox produce large panicles of fragrant flowers in various colors, adding height, heft, and charm to a border. Low-growing creeping phlox is effective as a groundcover at the front of the border, and as a rock and wild garden plant, especially in light shade. Phlox needs moist soil for optimal health.

Jupiter’s Beard

Also known as red valerian for its rosy pink flowers, Jupiter’s beard is one of the longest-blooming perennials in the garden (so long as you remove spent flower heads). Deadheading not only prolongs bloom but also prevents self-seeding. Unfortunately, Jupiter’s beard has escaped from gardens and become a non-native wildflower in some regions.