A relative of mint and lavender, forskohlii grows wild in India on the dry plains and in the foothills of the Himalayas. Other members of this genus of more than 150 species grow in the tropical and subtropical regions of the Indian subcontinent. The leaves are aromatic, with a camphorlike aroma, and have been used to cleanse and deodorize skin.
Common Names: Forskohlii, Hausa Potato
Description: Aromatic, herbaceous perennial grows up to 2 feet tall; bright green, ovate leaves with scalloped margins; clusters of blue-purple blooms on 10-inch spikes
Hardiness: To Zone 9
Flowering: Summer to fall
Parts Used: Leaves and roots
Range/Habitat: Dry hillsides and mountain slopes of India, Nepal, Thailand, and Sri Lanka
In India, where forskohlii is cultivated on a large scale, people eat the roots pickled or as a condiment.
This Ayurvedic herb could be beneficial in the treatment of a wide range of conditions, including asthma and other respiratory disorders, angina, congestive heart failure, hypertension, glaucoma, eczema, psoriasis, and insomnia. The leaves and roots of Coleus forskohlii are the source of a compound called forskolin, first isolated in the 1970s.
Research has shown that it has the potential to lower high blood pressure, relax smooth muscle tissue (such as in the bronchial airways), increase hormone release from the thyroid gland, and stimulate digestion. The compound also holds promise as a treatment for obesity: In recent preliminary clinical research conducted with men, the compound significantly reduced both their percentage of body fat and fat mass.
Caution: Scientific research on this herb is preliminary. What is known relates primarily to its compound forskolin, rather than the entire herb.
How to grow it
Forskohlii thrives in light, well-drained loam in sun or partial shade. In subtropical climates (Zone 9 and warmer), the herb can be grown outdoors as a perennial. In cooler climates, grow forskohlii as a potted plant; in fall, or when the temperatures cool, bring it indoors to a warm, sunny location.
Native to arid and semiarid locations, forskohlii is drought tolerant, so avoid overwatering. Indoors, provide the brightest light possible—a greenhouse is ideal. For medicinal use, collect the leaves and roots in fall, when the herb’s active constituents are at their highest levels. Propagate established plants by taking cuttings or by dividing the roots in summer.