• Platycodon grandiflorus
• (Plat-ee-KO-don gran-dih-FLOR-uss)
• Family Campanulaceae
• Perennial herb
Large, puffy buds opening to shallow, bell-shaped blossoms make balloon flower a favorite feature of the summer perennial garden. In the Far East, the plant’s fleshy roots have been consumed for their health benefits for more than 2,000 years.
The genus Platycodon (Greek for “broad bell”) contains a single species of herbaceous perennial native to Japan, Korea, northern China, and eastern Siberia. P. grandiflorus (Latin for “large flower”) grows in neat 1-foot-wide clumps. The smooth stems branch near their tops; they bear toothed, ovate green leaves up to 3 inches long, the lower ones arranged in whorls, the upper ones alternately.
Solitary flowers or small clusters bloom in mid- to late summer. Children can seldom resist popping the inflated buds (the “balloons”), which otherwise open into 2-inch upward-facing bells with five pointed petals, yellow-white stamens that are inflated at the base, and five stigmas. In fall, the foliage turns yellow, providing interest in the garden even after plants have stopped blooming.
P. grandiflorus grows about 2 1/2 to 3 feet tall and has blue single flowers, but cultivars are available in other colors, double flowers, and shorter stems. They include ‘Alba’, ‘Fuji Blue’, and ‘Double Blue’, 24 inches tall; ‘Hakone Double Blue’, ‘Hakone Double White’, ‘Mariesii’ (blue), and ‘Mother of Pearl’, 12 to 18 inches tall; ‘Baby Blue’, ‘Sentimental Blue’, ‘Apoyama Fairy Snow’, and ‘Apoyama Misato Purple’, 6 to 8 inches tall. ‘Komachi’, 16 inches, has dark blue buds that never open.
The taller forms may be placed in the middle of the flower bed, the shorter ones at the front. The smallest forms, which nevertheless have full-sized flowers, may be grown in containers and are often found in rock gardens. All thrive in Zones 3 to 10 except in southern Florida and along the Gulf Coast.
Good companions for balloon flower include golden feverfew, silver artemisias, nepetas, butterfly weed, malope, and sea lavender. White ones go well with globe thistle and gayfeather. Pink-flowered forms are lovely in part shade with lady’s-mantle and barrenworts. These seem to retain their color better in shade than in full sun.
Roots of balloon flower (jie geng in Chinese) are used to treat coughs, sore throats, and other respiratory disorders, as well as toothache and fatigue. They are thought to work by dilating the bronchial vessels; a constituent called platycodigenin thins and helps eliminate phlegm. Recent studies found that the root killed a liver fluke (internal parasite) and lowered “bad” and raised “good” cholesterol in rats. An ingredient of several Japanese herbal extracts, the root may be anti-inflammatory. A saponin in the root increases pancreatic secretion through the release of gastrointestinal hormones.
Koreans eat the root in soup as a tonic vegetable, pickled, or preserved in sugar. The Japanese serve the young leaves in salads. The flowers keep well in water if you first sear the base of the stems with a match.
Plants are late to emerge in spring, so mark them well. Give them well-drained sandy loam and full sun in the North, afternoon shade in the South.
The species and some cultivars are easy to grow from seed, but you’ll need to buy plants of other cultivars. Sow seed on top of moist potting mix; cover the container loosely with plastic wrap and set in a warm place. Seeds should germinate within two weeks at 70°F. To minimize handling the fragile seedlings, sow seeds sparingly into plastic six-packs, then snip all but the strongest seedling in each cell.
When the weather is warm, transplant seedlings to a nursery bed after hardening off, and move them to their permanent location in early fall for blooms the following summer. Balloon flower plants are long-lived and spread slowly. They may be propagated by division in spring when shoots first emerge or by basal cuttings containing a piece of root.
The plants are generally trouble-free. Snails, slugs, and rabbits sometimes take a liking to them.
• Carroll Gardens, 444 E. Main St., Westminster, MD 21157; (800) 638-6334. Catalog $3. Plants of P. grandiflorus, ‘Alba’, ‘Shell Pink’, ‘Apoyama Fairy Snow’,‘Apoyama Misato Purple’, ‘Double Blue’, ‘Hakone Double Blue’, ‘Hakone Double White’, ‘Mariesii’.
• Forestfarm, 990 Tetherow Rd., Williams, OR 97544-9599; (541) 846-7269. Catalog $4. Plants of P. grandiflorus, ‘Fuji Blue’, ‘White’, ‘Double Blue’, ‘Shell Pink’, ‘Sentimental Blue’, ‘Komachi’.
• Thompson and Morgan, PO Box 1308, Jackson, NJ 08527-0308; (800) 274-7333. Catalog free. Seeds of ‘Baby Blue’, ‘Fuji White’, ‘Mother of Pearl’, ‘T&M Mixed’.