How to Plant and Grow Balloon Flower

The inflated buds of balloon flower (Platycodon grandiflorus) are fun to pop, and they make great cut flowers. Cut them in the bud stage and sear the base of the stems to prevent the milky sap from seeping out and fouling the water. Most commonly available in blue-violet, balloon flowers also come in pink and white, as well as shorter forms that are better suited for rock gardens and containers. In fall, the foliage of balloon flower plants turns clear gold, so don't cut the plant down early—enjoy the show! They tolerate light shade but not wet feet or drought.

Where to Plant Balloon Flower

Plant balloon flower plants in a sunny part of the garden. You'll get the most blooms when the plant receives at least eight hours of sun daily. It will grow in part shade, but the number of blooms is substantially reduced. If needed, amend the soil to be organically rich, loamy, and well-draining by adding compost or organic material. Balloon flower prefers soil with a pH of 5.5-7.5, so test the soil pH level before planting and make any needed adjustments.

Balloon flower adds the desirable color blue to mixed beds, although white and pink cultivars are also available. Plant them where they are easily accessible. Kids (or grandkids) find them highly entertaining when they squeeze the sides of the closed blooms, causing them to pop open.

How and When to Plant Balloon Flower

Start seeds indoors in seed-starting mix six to eight weeks before the last frost date in spring for blooms the first year, or direct sow them on the surface of a prepared garden bed after the last frost date for blooms the second year. Either way, don't cover the seeds; they require light to germinate. Keep the soil or growing medium moist but not soggy.

Plant nursery starts in the garden in early spring for blooms the first year, or plant them later in the year for blooms the second year. Dig a hole in the garden the same size as the rootball. Remove the balloon flower from its container gently, being careful not to damage the roots, and set it in the hole at the same depth it was in its container. Firm the soil around it and water the plant.

Balloon Flower Care Tips

Balloon flowers are easy to grow and care for when their basic needs are met.

Light

Balloon flower plants grow best in full sun. They will grow in partial shade and might benefit from shade in the afternoon in hot climates.

Soil and Water

Balloon flower thrives in organically rich, loamy, well-draining soil with a pH between 5.5 and 7.5. Once established, balloon flower will usually succeed without extra irrigation; rainfall is normally sufficient. Water regularly, about an inch per week, during the plant's first year in your garden.

Temperature and Humidity

A temperature range of 60°F to 80°F is ideal for balloon flower plants. In hotter areas, provide some afternoon shade. These plants tolerate a wide range of humid and dry conditions.

Fertilizer

When the soil is rich, balloon flower doesn't require any additional fertilizer, although an application of compost in the fall invigorates the plants. In areas where the soil is poor, apply a balanced, slow-release fertilizer in the spring, following the product instructions.

Pruning

In spring, cut all the branches of balloon flower plants by one-half to encourage branching and bushy growth. After the season is over, cut the plants back to the ground. During the blooming season, deadhead the spent flowers to extend the season.

Potting and Repotting Balloon Flower

Balloon flower grows well in containers as long as the container is deep enough to accommodate the plant's long taproot; 10-12 inches is usually sufficient. As for width, the container should be at least 2 inches wider than the anticipated size of the mature plant. Good drainage is a necessity.

Balloon flower doesn't like to be transplanted. When it outgrows its current container, wait until the plant is actively growing before repotting, taking care not to damage the taproot.

Pests and Problems

Balloon flower plants are pest and disease resistant. However, they tend to experience root rot when grown in too-wet soil. Gardeners should keep their eyes open for snails and slugs that like to nibble on the blooms.

How to Propagate Balloon Flower

Gardeners can propagate their balloon flower plants in three ways: by collecting seed from a mature plant in the fall, from stem cuttings, and by division. Propagating with seed is a simple process. Working with stem cuttings is not much more difficult, but propagating by divisions is challenging and has a high failure rate due to potential root damage.

Seed: After a bloom dies, look for the brown pod at the end of the stem. Let it dry on the plant and then cut the stem and pod off the plant and place them in a paper bag. Pop open the pod to release hundreds of tiny seeds. In spring, after all chance of frost is past, dig compost into a garden bed in an area that receives full sun to part sun. Sprinkle the seeds on top of the bed, but don't cover them. Water the seeds and keep the soil moist until they germinate in about two weeks. Continue to keep the soil moist as the seedlings grow. If starting seeds indoors, sow them six to eight weeks before the last spring frost and transplant them when the weather warms.

Stem Cuttings: In the spring, take 4-inch cuttings from soft, growing stem tips. Remove the foliage from the bottom half of the cuttings. Dip the bottom end of the cuttings in rooting hormone and plant them in individual pots filled with a sterile planting mix or seed-starting medium. Cover each pot and plant with a clear plastic bag, and place the pots in a bright light (not full sun) location, keeping the soil moist but not soggy until the cuttings root. New leaf growth indicates the cuttings have rooted. Transplant the rooted plants to the garden, being careful not to disturb the roots.

Division: The long taproot of balloon flower complicates propagation by division. Divide the plant in the spring while it is still small. Dig a circle around the plant that is at least 12 inches away from the main clump of flowers to avoid damaging the root system and lift it from the ground. Using a sharp knife, cut down the middle of the taproot and plant, making sure each half of the taproot has at least one growth node. Replant the two halves immediately.

Types of Balloon Flower

'Astra Blue' Balloon Flower

Platycodon grandiflorus 'Astra Blue' bears large blue flowers on compact plants in late summer. It grows 8 inches tall and wide. Plant in zones 4-9.

Double Balloon Flower

Platycodon grandiflorus 'Hakone Blue' offers dazzling double blue flowers in summer. It grows 24 inches tall and 18 inches wide. Plant in zones 4-8.

'Sentimental Blue' Balloon Flower

Platycodon grandiflorus 'Sentimental Blue' bears purple-blue flowers in late summer on a compact plant. It grows 12 inches tall and 18 inches wide. Plant in zones 4-9.

Balloon Flower Companion Plants

Sedum

Varieties of sedum are practically perfect plants. They look good from the moment their flowers emerge from the soil in spring and continue to look fresh and fabulous all growing season long. Many are attractive even in winter when their foliage dies and it's left standing. They're also drought-tolerant and need very little, if any, care. They're favorites of butterflies and valuable bees. The tall types are outstanding for cutting and drying.

There are many different types of this beautiful plant, from tall ones that top 2 feet to low-growing groundcovers that form mats. All thrive in full sun with good drainage. Groundcover types suppress weeds but don't tolerate foot traffic. Some smaller ones are best grown in pots or treated as houseplants.

Helenium

Long-blooming helenium lights up the late-season garden with showy daisy flowers in brilliant yellows, browns, and mahogany, centered with prominent yellow or brown discs. Many of the best cultivars are hybrids. All are excellent for cutting. Deadhead to extend bloom time and divide the clumps every couple of years to ensure vigor.

Daylily

Daylilies are so easy to grow you'll often find them growing in ditches and fields, escapees from gardens. Yet they look delicate, producing glorious trumpet-shaped blooms in myriad colors. There are some 50,000 named hybrid cultivars in various flower sizes (the minis are very popular), forms, and plant heights. Some are fragrant. The flowers bloom on leafless stems. Although each bloom lasts only a single day, superior cultivars carry numerous buds on each scape, so bloom time is long, especially if you deadhead daily. The strappy foliage may be evergreen or deciduous.

Shown above: 'Little Grapette' daylily

Coreopsis

One of the longest bloomers in the garden, coreopsis produces (usually) sunny yellow daisylike flowers that attract butterflies. However, depending on the variety, coreopsis bears golden-yellow, pale yellow, pink, or bicolor flowers. It blooms from early to midsummer or longer if it's deadheaded.