By Beatriz Spalding
Lecturer in Ecology, Evolution and Organismal Biology
Iowa State University Extension
Basil, Ocimum basilicum, is perhaps the most popular culinary herb. Its refreshing sweet anise-like aroma is the perfect complement to tomato sauces and other mild-flavored foods such as eggplant and zucchini. Basil is the main ingredient in Pesto, a delicious bright-green and fragrant pasta sauce that would give any interested palate the ultimate basil experience.
Basil originated in Asia, India and Africa and since ancient times it was known to the Greeks, who called it the “Kingly Herb.” The name basilicum is derived from the Greek word basileus, which means kingly or royal. By the Middle Ages basil was well known throughout Europe, where it was used mainly for medicinal purposes. Later on, it became popular in the Mediterranean countries, especially Italy, where the mild climate favored its growth.
Botanically speaking, basil is an annual herb and a member of the mint family. Like its “mint” relatives, it has characteristic square stems, small flowers arranged in spikes at the tip of branches and aromatic oils in the leaves and flowers. The attractive foliage makes basil ideal for ornamental purposes as well. There are numerous types of basil available, with unique aromas and attractive habits, sure to please even the most demanding herb grower or landscaper.
Among the cooking varieties, ‘Sweet Basil’ is the most popular, often used in tomato dishes. Some varieties may have a citrus-like fragrance such as ‘Lemon’ and ‘Lime’ basil, and others have a cinnamon scent, like ‘Thai’ basil. For those interested in more unusual aromas, camphor and licorice scented basils also are available.
The varieties preferred for ornamental purposes offer different foliage colors, from light to dark greens to purple, along with distinctive growth habits and aromas. Among those with a green foliage is ‘Green Ruffle’ basil, with ruffled lime-green leaves and pink flowers, or ‘Magical Michael’ basil, with dark smooth green leaves and compact spikes of white flowers.
Dark foliage basils also include varieties with different color shades, from red to maroon to purple, or a mixture of colors and iridescence when seen under different light conditions. Among the purple basils, as they are known, is the popular ‘Dark Opal’ basil, an American-born variety, developed from a Turkish wild basil.
‘Red Robin’ and ‘Purple Ruffle’ varieties also make good choices to create a color accent in a dish or in the garden. Most varieties are available through catalogs or nurseries, or from local growers at farmers' markets.
Growing basil is quite easy as long as the right growing conditions are provided: full sun for at least six hours a day, and a moist and well-drained soil is preferred. Compact growth is encouraged by pinching off the growing tips, and a more abundant foliage and a sweeter flavor is obtained by cutting off the flowers as they appear.
Basil is susceptible to Fusarium wilt, a soil-borne fungal disease that may be prevented by planting in well-drained soils, avoiding excessive watering and rotating the planting site. Resistant varieties are also available, such as ‘Nufar’ basil.
Some of the most common basil pests are Japanese beetles, aphids, slugs and caterpillars. Spraying them with water may help get rid of these unwelcome visitors temporarily. However, additional control methods may be necessary.
So, whether thinking of embellishing your garden, deck or window box, or just thinking of giving your palate a royal experience, remember basil, the kingly herb.