My Amsonia Hubrichtii Arkansas Blue Star Is Not Blooming

Blooming Season

• Arkansas blue star only blooms once per year. Depending on winter climate and latitude, it blooms as early as April in the southern United States, or into early May farther north. Even if the old, withered flowers are trimmed away from the stem tips, no reblooming occurs. You'll have to wait until next year to enjoy the floral display. If you purchased a containerized plant in summer or fall and planted it in the ground, do not expect it to bloom.

Planting Depth

• One of the most common causes of perennials not blooming well is accidentally planting them too deeply. Look at the base of the Arkansas blue star, noting the orientation and color of the stem bases. You should see the stem emanating from a common general area right at the soil line. Piling soil atop the crown -- the transitional tissues from above ground stem to the matrix of spreading roots -- can stress the plant and lead to disease or rot problems. Deep planting often diminishes or prevents flowering. Dig up and replant the perennial so the crown is equal to or no more than 1/4 inch above the soil line. Keep the soil evenly moist to help the roots to reestablish and not dry out, especially in summer.

Environmental Stresses

• If the Arkansas blue star sprouts new stems and leaves in spring but does not produce any flowers by mid-May, other stresses may be occurring to make the plant less than healthy. The soil should be moist, but never soggy. A well-drained soil is needed to prevent root rot. Flowering may not occur if the plant doesn't receive enough light. Arkansas blue star prospers in full sun to light shade, but no less than four hours of uninterrupted sun exposure daily.

Other Tips

• As a prairie plant, Arkansas blue star does not need overly fertile soil. In fact, soils rich in nitrogen, often the resulting from overfertilization, may diminish flowering while promoting lots of leafy green growth. Planting this perennial in sandy soil may be problematic, too. Organic matter is needed to make a sandy soil more fertile and retain moisture better. Although slow-growing, after three to five years of growth, the plant may benefit from digging up and dividing in early spring, before the stems are taller than 1 inch. Improved plant vigor and performance often follows after being divided and replanted.