This essential herb offers a world of scents and flavors -- no other herb is so exuberant and so useful. You may pick a sprig of rosemary or thyme, or a few fronds of parsley or dill, but you'll pick an armload of basil!
While basil is perhaps most associated with Italian foods, it can also be found in dishes from cultures around the globe. Different varieties of basil have slightly different flavors: lemon basil has a citrusy flavor and scent; Thai basil spices up Thai and Vietnamese dishes. Basil leaves can even be added to fresh salads. And nothing says summer like fresh pesto made from home-grown basil!
In addition to their culinary value, many varieties of basil are decorative as well. The rich purple-black foliage of purple basil complements almost any plant, especially orange and yellow annual flowers.
Thai basil has both an unusual taste and handsome appearance. Its flavor is spicier than other basils, with licorice overtones, and its smooth leaves and deep red-purple flowers contrast nicely with white flowers.
You have a few options for getting started. You can purchase seedlings (also called transplants), start your own seeds indoors, or sow seed directly into the garden.
Note that, like peppers and melons, basil requires warmth, so plan to wait to set transplants outdoors until night temperatures are consistently above 55F, or at least a week after the average last frost date. And hold off on mulching the new transplants until the soil is thoroughly warmed up.
Starting from seed indoors. Start seeds 4 to 6 weeks before you plan to set them outdoors. Sow seeds 1/8-inch deep and keep the containers warm. The seeds should germinate in about a week. As soon as you see the shoots, place the seeds under grow lights (or regular fluorescent lights), keeping the lights just a few inches above the plants. Once the seedlings have 2 or 3 sets of leaves, pinch off the growing point. This will stimulate the plant to produce 2 shoots at that spot. As the seedlings grow, continue pinching the growing tips back for bushier growth.
Moving outdoors. Keep in mind that basil likes warm temperatures, so don't rush to bring seedlings outdoors. And be sure to acclimate seedlings to the harsher outdoor conditions by hardening them off: Place plants in a sheltered location for an hour or so the first day, increasing the amount of time the spend outdoors over a week or two.
General care. Basil likes a fertile soil, though it tolerates a wide range of pH (4.5 to 6.5). Although some folks insist that the flavor is better if basil isn't fertilized, the plants grow faster and look better if they're fed at planting time, and again during the season, perhaps after a heavy picking. Unlike some herbs, such as thyme and sage, which can tolerate some drought, basil requires a consistent supply of moisture.
Pests. Like most herbs, basil has few pests. Japanese beetles can easily be kept off with row covers. If slugs are a problem on new transplants, trap them with beer-baited traps. Minimize disease problems by planting in well-drained soil, spacing plants so they dry out after they're watered, and practicing good garden sanitation.
The optimum time to harvest basil is just before it flowers -- at this point the leaves have their maximum essential oil content, which gives them their flavor and aroma. If you are planning on one big harvest -- perhaps for a batch of pesto or for freezing or drying -- wait to harvest until you see flower stalks beginning to form. However, you can also harvest sprigs throughout the summer. Each time you harvest a sprig, pinch the stem back to a set of leaves.
Store basil at room temperture in perforated or loosely tied plastic bags, or place the stems in water, changing the water daily as you would for cut flowers.