Basil Plant Facts

Varieties and Uses

• Cahill states that more than 160 varieties of basil exist. Sweet and Italian basil are among the most common varieties grown in the home garden. Exotic "dark opal" basil develops deep purple leaves. More unusual varieties include lemon basil, cinnamon basil and licorice basil. Basil is used as an ornamental plant, as a culinary herb and as an ingredient in jellies, vinegars and teas. It is also used to relieve digestive problems, vomiting, constipation, headaches and anxiety, according to Cahill.

Seeds vs. Transplants

• Jeanne Youger-Comaty of Ohio State University Extension said basil is easy to grow, whether seeds are started indoors in advance or directly in the garden. Basil, however, is a tender plant that will not tolerate frost or cool temperatures, so starting seeds indoors provides a head start that will result in an earlier harvest. Basil requires a soil temperature of 70 degrees to germinate.

Starting Seeds

• Sow seeds approximately 1/2-inch apart in a flat filled with a sterile growing mix. Keep the soil moist until the seeds germinate, usually in five to seven days. Seedlings can be transplanted to individual pots when they have two pairs of true leaves. When outdoor temperatures have warmed, harden off plants by leaving them outdoors for increasingly longer periods of time each day, for about five days.

Transplanting

• Prepare the soil in a sunny location with good drainage. Plant seedlings 12 inches apart. Do not fertilize unless the soil is especially depleted, Youger-Comaty said, since fertilizing will decrease the aromatic oil in the plants. If the plants are to be used for culinary purposes, remove flower buds as they appear. Prune every two or three weeks to encourage fuller growth.

Harvesting and Preserving

• Harvest leaves by cutting a stem about a 1/4 inch above the junction where a pair of leaves has emerged. Leave enough of the plant intact so it can continue growing through the season. Leaves can be dried by hanging in a dry place, or by microwaving on low power for up to three minutes. Basil can also be preserved by freezing the leaves in ice cubes or mixing them with oil or vinegar.