Scutellaria lateriflora L. is native to North America and can be found east of the Rocky Mountains in the temperate zones. A member of the Lamiaceae family, skullcap is widely distributed in woods, moist thickets, marshes, and on the banks of streams. It is an herbaceous perennial that grows to a mature height of twenty-four to thirty inches. Leaves are ovate to ovate-lanceolate with serrated margins. The blue flowers bloom from July to September with blossoms only on one side of the flower stalk. The plant spreads through slender stolons and can fill in an area rather quickly. It is the aerial part of the plant that is harvested and used for medicinal purposes.
The Cherokee Indians used skullcap as part of a concoction given to women to promote menstruation. It was also used for diarrhea and breast pain. In the early 18th century in America, Skullcap was used in the treatment of rabies and was given the nickname “Mad Dog”, though it is unclear as to its success for treating rabies. Today, it is used for digestive problems as well as a nervine and mild sedative for the treatment of anxiety, depression, and insomnia.
selecting a planting site
Although seed is commercially available, site selection is difficult. Skullcap requires areas of constant moisture, such as moist thickets or marshlands, to grow. It prefers a fertile soil, is hardy to zone four, and grows well in full sun or partial shade. When growing in a hot, dry area, shade and moisture must be provided. Once harvesting begins, fertilize with a high nitrogen compost.
Skullcap can be grown through direct seeding, transplanting, or dividing the roots. Johnny’s Selected Seed Co., Winslow, Maine, recommends the following guidelines for starting seeds. The preferred method is to start seeds indoors. Skullcap seed requires a cold stratification period and light to germinate. Sow seeds shallowly in flats with a prepared soil mix. Moisten and refrigerate at 40-500F for seven days. Flats can also be placed outside where the seeds will be exposed to nighttime cold temperatures. After the required stratification period, put flats in the greenhouse for germination. Seeds should be started six to eight weeks before setting out in the field. In late spring, transplant outside in well-prepared soil. Space plants eight to twelve inches apart in rows one and one-half to three feet apart or in three-foot wide beds. Once established, plants will spread quickly to fill the bed. It is very important to keep the beds and rows weeded.
Direct seeding can be done outside in spring. In a well-prepared planting bed, shallowly sow one to two seeds per inch using the recommended row spacing. When plants have several sets of true leaves, thin eight to twelve inches apart. Do not allow the seeds to dry out and keep the planting beds free from weeds. Once plants are established, root divisions can be made in spring or late fall. This is the preferred method by Tim Blakley, Medicinal Herbs in the Garden, Field, and Marketplace. Transplant divisions immediately at the recommended spacing and keep moist.
insects and diseases
Diseases for skullcap, listed in Index of Plant Diseases in the United States, include the leaf spots, Cercospora scutellariae, Phyllosticta decidua, and Septoria scutellariae; stem rot, Botrytis cinerea; powdery mildews, Erysiphe galeopsidis, and Microsphaera sp.; and root rots, Phymatotrichum omnivorum and Rhizoctonia solani.