Provide lots of sunshine and warm temperatures for your basil plant. Because basil can't tolerate temperatures below 50 degrees, keep nighttime temperatures no lower than 55 degrees. Temperatures in the range of 65 to 70 degrees in the daytime are ideal. The basil plant also requires a well-drained, nutrient-rich planting mix, with a pH between 6.0 and 7.5. Check the pH monthly with the testing kit.
Water the basil plant well and maintain a moist soil. Empty any water that remains in the drip pan after watering.
Fertilize your basil plant with a diluted solution, preferably half-strength, every two or three weeks. Use organic fertilizer if the basil will be used in cooking.
Pinch off the flower buds as they form. This will encourage more foliage growth and make your basil plant bushier.