New Ornamental Basils

Basils (Ocimum spp.) are very rich in a wide range of chemical constituents, many of which have industrial value. Besides commercial use by the perfume, pharmacy, and food industries for its natural aroma, basil is more commonly familiar in the U.S. as a potherb, grown for its flavor and delicacy as a spice, and its beauty and fragrance as an ornamental. In addition to unique types that are rich in specific chemical constituents, many new forms and aromas have been discovered that may have consumer appeal as ornamental herbs. One type includes a new form of lemon basil. Presently, basils which exhibit a lemon aroma and are commercially available are very short, flowering early in the summer, have small and narrow leaves, and contain a low concentration of essential oil and a low relative percent of citral in the oil. (Citral is comprised of neral and geranial, chemicals that jointly cause that ‘lemon’ aroma.) In 1989, Jim Simon, Mario Morales, Ernie Cebert, and Denys Charles, of the New Crops Center, identified a single robust, tall basil plant with an intense, fragrant lemon aroma. The plant, distinguished by a distinct upright growth habit with larger leaves, appeared in one of the large intermated breeding populations. This plant was cloned and served as the parent to develop a new ornamental lemon basil.

After two cycles of selfing and selection, five uniform lines of lemon basil were identified with desirable aromatic, horticultural, and ornamental characteristics. Plants exhibited a strong, pleasant lemon aroma and, compared to commercially available lemon basil varieties, had a larger leaf size (similar to sweet basil genotypes) and taller stature.

Both available lemon basil varieties and the new lemon basils described here have attractive white flowers which continue to bloom as the plants continue to grow until frost. Each line has a distinct lemon fragrance (citral content <65% in 1991). Each of these lines is highly aromatic (essential oil contents of 0.55 to 0.75% oil/g dry weight in 1990). Each of these lines appears highly vigorous with plants reaching heights of 58 to 65 cm (1991). Lines 75, 77, and 47 appear to be more aromatic, vigorous, and uniform than the original plant that was used as a check and their sister lines (78 and 48). This new lemon basil has generated much interest and will soon be released and available to the commercial herb industry.