Abstract

Helianthus debilis Nutt. ssp. debilis ‘Flora Sun’, ‘Flora Sun’ beach sunflower, is a native, herbaceous perennial that should be propagated by cuttings to maintain its genetic and phenotypic fidelity. Stem cuttings were treated with a quick dip of a potassium salt of 1H-indole-3-butyric acid (K-IBA) solution at 0, 250, 500, 1000, 1500, 2000, 2500, or 3000 mg/liter (ppm) and rooted under intermittent mist. The root systems of six of twelve cuttings were harvested 17 and 21 days after treatment. The remaining six cuttings were transplanted in a soilless substrate to determine the effects of K-IBA on establishment in containers. Treatment of stem cuttings with K-IBA increased the number of roots and root fresh weight when cuttings were rooted under summer greenhouse conditions, but K-IBA did not provide any substantial short-term benefits in survival or growth of rooted cuttings after they were transplanted into plastic containers.