Balloon flowers (Platycodon), also known as Chinese bellflowers, have balloon shaped buds that pop open into beautiful blue, white, pink, or purple flowers in summer. Balloon flowers can be slow to establish and emerge late in the spring. Otherwise, they are long lived and low maintenance plants.
Balloon flowers are native to China and Japan. They are non-aggressive and non-invasive, so are safe to plant in your flower beds. They are also deer resistant.
Balloon flowers are hardy in zones four to nine. Sometimes they are hardy in zone three as well, depending on where they are planted. Balloon flowers like full sun in cool areas and afternoon shade in hot areas. They also tolerate acid soil and soil with low fertility. They do need well drained soil, however.
Balloon flowers are perennial flowers that grow to be two and a half to three and a half feet tall. Some dwarf varieties are just six inches tall. They spread half a foot to a foot wide. The blue, violet, pink, or white blooms come during the summer. The buds can be popped like a balloon, hence the name.
Balloon flowers are grown from seed or from division of existing plants. Seed is planted in the fall and will sprout in the spring. Divisions should be planted in the fall. Dig a hole as deep as the roots and twice as wide. Place the balloon flower in the hole, spreading the roots well. Fill the hole carefully and firm the soil. The tap root should be about one to one and a half inches under the top of the soil. Water the plant in well. The tap root should not be showing at this point. Space plants about twelve inches apart. They look best in groups of three plants.
In the spring, when new growth appears, apply a complete plant food such as a 10-10-10 fertilizer. If using granular fertilizer, water the plant well after fertilizing.
Balloon plants require regular water. Aim for moist soil but not soggy soil. Root rot will occur if the soil is kept too wet.
Balloon plants can benefit from plant stakes or tomato cages to support them. Place the cages when the plants are young and they will grow inside them and use the cages for support. Otherwise tall plants will fall over.
Deadhead the blooms to encourage re-blooming. Cut the wilted flower stems to the ground with flower shears. In midsummer, cut the whole plant down by one quarter to encourage continued blooming. In the fall, after the plant fades, cut the whole plant down to the ground. Spread a layer of mulch over the plant to protect it from the winter chill. In the spring, remove the mulch so the plant can grow again.
Balloon flowers are very vulnerable to slugs. They will eat the plant down to the ground. You can pick the slugs off by hand if you garden organically. Otherwise, you can use iron phosphorous bait such as Sluggo and Escar-go. These baits are much safer than the old copper baits, which could kill pets and small children if eaten by them.