Basil is an easy to grow warm season herb that is popular in a variety of culinary dishes. Basil, according to the Clemson University Extension, is originally from India, but is also native to islands of the south Pacific, says the Minnesota University Extension. Basil includes 150 species from Asia, Africa and South Africa.
Sunlight and Heat
Basil thrives in full sun conditions. Basil requires six to eight hours of sunlight a day, according to the University of Minnesota. Germination of basil seeds takes five to 10 days once the temperature reaches 70 degrees F. Plants require planting once temperatures are consistently in the 70s. Basil will withstand nighttime temperatures of 50 degrees F and above. Basil requires a covering of pine straw if frost is threatening.
Fertlization and Soil
Basil requires a well-draining soil with a pH between 6.0 and 6.5. If lime is required to balance the soil's acidity, it is best applied during the fall, says the Clemson University Extension. Fertilizer should be applied according to a pH test result. If a soil test is not taken, apply 3 pounds of a 5-10-10 fertilizer per 100 square feet, mixing the fertilizer into the soil when the basil is planted.
Basil seeds are sown at a depth of 1/4 inch once the temperature outside is appropriate, according to Iowa State University. Rows are best thinned once the seeds germinate so that there is a 12-inch spacing between plants. Rows of basil are best spaced two feet apart. Seeds planted indoors are started six weeks before the last frost. The soil is covered with a growing medium and left at a temperature of 70 degrees F, and the soil is kept moist. Plants are carefully lifted from their pot and placed outside in the soil once the danger of frost passes.
Terminal growth of basil plants is best pinched off once the plant is mature to encourage lush growth and more tender leaves for harvest, says Clemson University Extension. Basil plants produce flower buds during the summer, which require pinching off to produce more flavorful foliage. Leaves are best pinched off the end of the basil branches, one or two leaves at a time.
Secondary Fertilization and Watering
Basil plants require a second fertilization two months after planting with 1/4 to 1/2 pound of calcium nitrate over a 100-square-foot area. The area requires mulching before fertilization to prevent runoff and promote moisture retention. Water the plants with a hose or a watering can at the base of the plant. Do not water the foliage as this may cause disease and burning.