Platycodon Grandiflorum [plat-ee-KO-don, gran-dih-FLOR-um] is an herbaceous perennial plant from the Campanulaceae family and the only plant in the Platycodon genus.
It’s native to East Asia, Japan, Korea, China, and far eastern regions of Russia.
It’s also widely grown in different parts of the United States.
This plant is also known by the botanical name, Campanula Grandiflora; however, it is generally known as the balloon flower plant, regarding the balloon-like shape of its flower buds.
Other common names of p. grandiflorum include:
- Chinese balloon flower
- Chinese bellflower
- Japanese bellflower
Balloon Flower Care
Size & Growth
Balloon flower reaches an average height of 24” inches.
This small herbaceous plant features dark green leaves, thick roots, and beautiful flowers.
Flowering and Fragrance
Campanula Grandiflora produces beautiful bell-shaped blue flowers in late summer, i.e., July and August.
There are varieties available with purple, white and pink colored flowers.
While the flowers are showy and attractive, the plant has gained popularity mainly due to the unique shape of its buds.
Before opening, the flower buds swell like balloons; hence, the common name.
Light & Temperature
Platycodon grandiflorum grows best and produces more flowers in full sun but also grows well in partial shade.
In areas where summers are too hot, some afternoon shade is recommended.
The ideal temperature for this plant is 60° – 80° degrees Fahrenheit (15° – 27° C).
But, it will tolerate higher temperatures with some afternoon shade and humidity.
Chinese bellflower cannot tolerate very harsh winters and typically dies down completely when the temperature drops below 5° degrees Fahrenheit (-15° C).
However, it’s hardy and may grow back in late spring and even produce flowers in summer after such a winter.
Watering and Feeding
Campanula Grandiflora doesn’t need much water once established and will easily handle short periods of drought.
Chinese bellflower is not a heavy feeder, but it benefits from the top application of compost in the fall.
It helps the plant regain the energy it lost during the blooming season.
Feeding the plant with a granular organic fertilizer in the spring helps it grow better.
Soil & Transplanting
Japanese balloon flower requires slightly loamy and well-draining soil and prefers a slightly acidic soil pH; within the range of 5.8 to 6.8.
Make sure the soil doesn’t stay too wet as it increases the chances of root rot.
Balloon flower plants rarely need division.
Grooming and Maintenance
Campanula Grandiflora prefers not to be disturbed.
However, deadheading encourages repeated blooming and helps maintain a good appearance.
When deadheading, only remove the faded or damaged flowers and not the whole stems.
How to Propagate Platycodon Grandiflorum
Japanese bellflower is propagated through seeds or plant divisions.
- When growing through seeds, make sure to stratify them before sowing and start indoors in early spring.
- Sprinkle the seeds on the top of moist soil and lightly press it in with your hands; do not sow the seeds deep inside the soil.
- This is important because the seeds need light to germinate.
- The seeds take two to three weeks to germinate.
- Transplant the seedlings into bigger pots and harden off before planting or permanently moving them outdoors.
Hardening off is the process of gradually introducing the seedlings, grown in controlled conditions, to direct sunlight and other environmental conditions, such as the cold and air.
It involves keeping the seedlings outdoors only for some time and then bringing them back indoors.
The exposure time is gradually increased with each day, so the young plants get time to adjust to strong environmental conditions.
According to experts, the process of hardening off should ideally be continued for 7-10 days.
Propagating campanula Grandiflora plants through division is a little tricky because it has a long taproot and a thick and chunky root system.
The plant also doesn’t like to be disturbed.
- When using this method for propagation, experts recommend slicing a piece off the plant using a sharp knife instead of digging it up.
- However, make sure the piece you cut off has at least half-an-inch piece of the root.
- Plant this piece in a pot and keep the soil consistently moist (but not too wet) until it is established.
No matter what method of propagation you use, do not expect the new bellflower plant to bloom in the first season.
Platycodon Grandiflorum Pest or Diseases
Apart from the possibility of developing root rot, when the soil consistently remains too wet, the plant isn’t susceptible to any major disease.
Chinese bellflower is also considered deer resistant.
Balloon Plant Uses
The balloon flower plant is grown for ornamental purposes in most areas.
However, in Korea, it is primarily grown for consumption.
The plant, along with its roots, is widely consumed in Korea in various ways because it’s believed to offer a variety of health benefits.
It’s also used for medicinal purposes in both China and Korea.
In traditional Chinese medicine, the plant is used for treating the common cold, cough, and associated symptoms.
In Korea, the roots of platycodon grandiflorum are used for treating several diseases as they are believed to have powerful anti-inflammatory and anticancer properties.
Balloon flower root is believed to help treat insulin resistance in the body.
Different types of plant extracts are made from this plant and used for medicinal purposes.