Last Updated on August 16, 2022 by Plant Mom Care
Platycodon grandiflorus or balloon flowers, a species of perennial flowering plants from the Campanulaceae family, the sole member of the Platycodon genus. It is indigenous to Eastern Asia and is also called the Chinese bellflower.
This plant grows about 24 inches high with a width of 12 inches, with dark green foliage. The leaves are 2 – 5 inches long, with notched edges and narrow ends. It has thick roots and exudes white sap when cut. A noteworthy feature of this plant is its flower buds, which swell like balloons before opening.
The five petals form the shape of a bell at the base, opening into star-shaped flowers of 2 – 3-inches. This easy-growing plant flowers throughout summer, producing vibrant blue-violet flowers, although there are also some cultivars with pink and white flowers.
They are typically planted in spring when the cold of winter has passed, growing rapidly and flowering in the first year. It commonly grows in fields and mountains in its native habitat. It dies down in winter and reappears in late spring.
This plant is grown largely as ornamentals, although it is primarily cultivated for consumption and medicinal purposes in Korea and China.
Taller varieties that can become floppy might have to be staked or planted in clumps to support each other. These plants can ideally be grown in borders in landscape and home gardens, including rock gardens, with their wide-open flowers attracting several insect pollinators like bees and butterflies, and others.
They can self-sow, although they don’t spread aggressively. Generally, they are fairly low-maintenance and are mostly pest- and disease-resistant except for instances of root rot in places that get plenty of rainfall.
Balloon Flowers Light Requirements
They prefer growing under the full sun (6 hours every day) and producing more flowers in these conditions. However, they also tolerate partially shaded areas and benefit from some shade if the afternoon sun is particularly hot.
Balloon Flowers Watering
Young plants need consistently damp soil, but not soggy conditions. Once mature, they prefer a modest amount of water, although they can endure drought for short periods. They don’t require plenty of watering unless they are growing in locations with long periods without rain that makes the soil dry.
Balloon Flowers Humidity
They can tolerate both dry and humid conditions if they have appropriate amounts of water.
Balloon Flowers Temperature
These plants are hardy down to −40°F and grow well in USDA zones 3 to 9. Their ideal temperature ranges between 60 – 80°F but can bear higher temperatures if they get shade in the afternoons, young plants will die in frosty conditions, also causing mature plants to die down in autumn and grow back in spring.
Balloon Flowers Soil
They prefer rich organic and loamy soil with decent drainage. They won’t grow well with dense clayey soil. They also like slightly acidic soil.
Balloon Flowers Repotting
These plants grow in clumps and don’t spread much. However, if you feel they need to be repotted, do so in spring or autumn. Water well a day before removing them from their container to avoid damage to the taproot. This is easier when the plant becomes dormant.
Prepare a new container with respectable drainage capacity and add some fresh soil to the bottom. Lift the plant out from its old home and transfer the plant, topping up empty spaces with fresh soil. Keep it out of direct sunlight and water well.
Don’t worry if the plant looks less vigorous after repotting – it needs a little time to recover.
Balloon Flowers Propagation
Propagating these plants by division is usually not suggested as the deep taproots don’t like being disturbed. Propagation by seed or stem cuttings is better.
Propagation from seed
Start seeds indoors during early spring or about two months after your location’s last predicted frost, filling a seed tray or pot of starter mix or regular potting soil.
Lightly sprinkle soil on the seeds, placing the tray or pot in a warm area until germination occurs. When the weather turns warm, transplant the seedlings into separate containers or outdoors but remember that they most likely won’t bloom in the first year.
Propagation from cuttings
Prepare a small pot/container of starter mix or regular potting soil. Cut a 4-inch long stem and remove leaves at the lower half, use rooting hormone on the end if you desire, and then insert it in the moist soil.
Keep the soil damp but not waterlogged until the time the roots start to appear. Once you see new leaf growth you’ll know that rooting has taken and watering can be scaled but to your normal practice. The new plant can now be transferred to a container or the garden.
These plants usually don’t need additional feeding if they are growing in rich organic soil but adding a fresh layer of compost in autumn or spring will help replenish and freshen the nutrients they expended on flowering during the previous growing season. However, if the soil they grow in is poor, add all-purpose slow-releasing fertilizer before the new foliage appears in early spring.
Pruning isn’t generally necessary with these plants although you can do some light pruning to improve the appearance of the plants. To get bushier plants, you can prune back taller stems by half in late spring.
This will also help prevent flopping as the plants grow. Deadheading spent flowers will keep them healthy to produce more blooms. Don’t prune away entire stems, just the dead or faded flowers as buds remaining on the stem will continue opening. This also encourages the production of more buds.
Balloon Flowers Common Problems
Slugs and snails usually plague these plants. Traps or suitable bait can control and eliminate these pests. However, these plants can get infected by crown rot, botrytis mold, root rot, fungal leaf spot, or powdery mildew.
Crown rot and root rot might kill the plants. Leaves with spots or blotching must be removed and the plant sprayed with an appropriate fungicide to prevent the spread of the infection. Plants affected by mold must be discarded quickly to stop spreading to other plants nearby. Use an appropriate fungicide on the other plants to protect them.