Platycodon: Balloons for a Garden Party
Some flowers in the garden are refined and elegant, while others are loud and boisterous; and some are just plain fun. For me, Platycodon falls in the latter category. The botanical “Latin” name of this east Asian native is derived from two Greek roots: platy, meaning “broad,” and kodon, meaning “bell.” These plants are part of the larger bellflower family (Campanulaceae), and “broad bell” aptly describes the shape of their flowers.
Only one species of this genus, Platycodon grandiflorus, is listed in my garden reference books, and it is the species I am growing in my garden. The fun feature of this plant is best captured by its common name of “balloon flower;” the flower buds start off small and green, and then they puff up bigger and bigger, acquiring their flower color just before they burst open from the top.
If you happen to be paying attention at the right moment, you might see the first flower petal begin to lift, just before the flower fully opens.
Pay attention after the flower opens, and you can see the inner parts of the flower unfold over the following days. At first, the stamens and pistil seem to form a solid unit at the center of the flower. Then, the stamens spread away from the center and lie flat against the base of the petals. Once that happens, the pistil also begins to open, forming a white star shape at the center just before the flower fades. The whole process can happen in just a few days in warm weather. But in cool fall temperatures, each stage can last for several days.
I have Platycodon grandiflorus growing in many parts of my garden. It likes full sun and well-drained soil and is easy to grow in my sandy conditions in Maine. Most reference books describe Platycodon as growing about 2’ – 2 1/2’ tall, but it typically reaches heights of about 3’ in my garden. Most books recommend that you not try to divide these plants because they don’t like to be disturbed and are easily propagated from seed. The usual advice is to put them where you want them and then leave them alone to form a big clump. I have never tried to divide a Platycodon plant, but I have successfully moved them in the spring. I occasionally find self-sown seedlings (always blue) in my garden, and I consider these volunteers a special treat.
Balloon flowers come in three colors – blue, pink, and white, and I have all three growing in my garden. One of the virtues of this plant is that it blooms in late summer, after many flowering perennials have passed their peak. In my Maine garden, the first balloon flower to bloom is usually the dwarf variety ‘Sentimental Blue,’ which opens its first flowers in mid-July. It is followed within a week or so by the tall blue variety, and then about a week after that, by the very lovely ‘Shell Pink.’ The plants in my back garden bloom somewhat later than those on the back slope (perhaps because they get a bit less sun), with the blues opening their first flowers in late July and the pinks in early August. The white-flowered plants are the last to bloom (in mid-August in my garden), and I have found their flowers smaller and the plants less vigorous.
Platycodon flowers continue to open over a period of several weeks, and they will make a second flush of flowers if they are faithfully deadheaded. (In my Gettysburg, Pennsylvania garden, the last of the balloon flowers just finished blooming this week.) I have found that cutting the foliage back about 1/3 in June results in fuller, bushier plants and slightly delays the onset of their bloom period. (I learned this trick from the deer who browsed my Platycodon plants one summer.) I find that tall plants sometimes tend to flop over; when they do, I use peony hoops to provide them with some discreet support. Because Platycodon are the last plants to emerge in spring (looking like asparagus spears as they poke up out of the ground just when you had given up on them), it is also helpful to mark their place so that you don’t accidently damage their crowns when cultivating nearby.
Platycodon grandiflorus is a rewarding, easy-care plant that provides many weeks of color in the garden. Children love to watch its buds puff up and burst open, and it makes a wonderful, long-lasting cut flower (but only if you sear the end of the stem with an open flame just after cutting). It is rated as hardy in USDA zones 3-8. Growing this fun flower makes every day feel like a party in the garden.