Liatris, commonly called Blazing Star or Gayfeather, is a popular perennial valued for its striking, spiky purple flower heads that attract butterflies and other pollinators. The plant grows from a structure often mistakenly called a bulb, but it is correctly identified as a corm. Successfully establishing this perennial in a garden depends heavily on correct planting, especially knowing the proper orientation of the corm.
Identifying the Corm Orientation
The Liatris corm is a swollen, underground stem base that stores food, distinguishing it from a true bulb. Determining the correct “up” direction is a common challenge because the corm does not always have a clearly defined point. The top of the corm is the growing point, which may appear slightly pointed or feature small, pale sprout remnants from the previous season’s stem, sometimes called “eyes” or the crown.
The bottom of the corm, known as the basal or root plate, is typically flatter and sometimes covered with fine, shriveled roots. When planting, the corm must be situated with the growing point facing directly upward to allow the shoot to emerge efficiently. If the corm is perfectly smooth or its orientation is ambiguous, the best practice is to lay it horizontally within the planting hole. The plant’s natural geotropism will allow the sprout to bend and grow toward the soil surface, though this may cause a slight delay in emergence.
Practical Planting Steps
Liatris corms should be planted about 2 to 4 inches deep, depending on their size. Larger corms benefit from a deeper placement, closer to the 4-inch mark, to provide better anchorage for the mature plant.
Proper spacing is important for air circulation and robust growth, requiring corms to be set 12 to 15 inches apart. To plant, dig a hole to the required depth, place the corm with the growing end facing up, and then gently backfill with soil. This ensures the developing roots have room to spread and the emerging shoot is correctly positioned for vertical growth.
Site Selection and Initial Care
Liatris is native to North American prairies. The optimal time for planting the corms is in the spring, after the danger of the last hard frost has passed and the soil is workable. Planting can also occur successfully in the early fall.
A location that receives full sun is ideal for Liatris, as this light exposure produces the strongest, most upright flower stems. While the plant can tolerate some partial shade, at least six hours of direct sunlight is necessary for best results. Well-draining soil is a requirement; Liatris will not tolerate standing water, which causes the corms to rot.
Immediately after planting, water the area thoroughly to settle the soil around the corms and initiate root growth. After this initial watering, it is important to allow the soil to dry out between waterings. Liatris is relatively drought-tolerant once established, so excessive moisture should be avoided, as this can be detrimental to the corm’s health.