The balloon flower, also known as platycydon grandiflorus, is a native plant to Northeast Asia. The balloon flower is a perennial which can be grown in all zones, but is considered hardy in zones 3 through 8. Flowers appear in early summer, to late autumn, as rounded, balloon-shaped buds which open to form 2 to 2 ½ inch wide, star-shaped cupped flowers. The colors of the balloon flower come in blue, white and pink.
Planting Balloon Flowers From Seed
Approximately 7 to 8 weeks before spring, put seed starting soil into plastic planting cells until they are filled. Firm down the soil in each, then water until the soil is damp to the touch.
Sprinkle a few balloon flower seeds onto the soil. Push them in firmly into the soil. Cover the balloon flower seeds with no more than a light scattering of the seed starting mix, approximately 1/16 of an inch.
Loosely cover the cells with clear plastic wrap. Put the cells where the temperature will remain around 65 to 70F, and where there will be at least 6 to 8 hours of light available daily. Check the balloon flower seeds at least once a day. Don't let the soil dry out in the cells. Spritz them with water often enough to keep the topsoil moist.
Germination for balloon flowers is generally between 2 and 3 weeks. One seedlings emerge, remove the plastic wrap and place the cells into an irrigation tray to start watering from underneath. (See tips secont for instructions on watering from underneath). Keep the cells in the sunny, warm location. When they have grown to approximately 1 to 1 ½ inches tall, thin them down by removing the spindlier seedlings and leave the seedlings which appear healthier.
Once there is nor further danger of frost and seedlings are at least 3 to 4 inches tall, transplant them outside.
Transplanting Balloon Flowers
Choose a location which has full sun, or partial shade, with a rich, loamy type soil. Prepare the location by turning over the soil to a depth of 5 to 6 inches. Don't leave any sticks, rocks or weeds.
Dig holes 1 ½ times the width and depth of each planting cell. If planting a group of balloon flowers together, space holes 12 to 18 inches apart.
Remove a balloon flower seedling from a cell by forcing it up gently from the bottom of the cell. Place the seedling gently into the hole. Use care when transplanting, balloon flowers don't like their roots disturbed. Fill the hole up with water, and let drain before proceeding. Push in soil around the seedling until the hole is filled up with soil. Pack the soil down around the seedling. (See tips section for more information on caring for balloon flowers).