Soil

• Grow basil plants in average to rich soil that is light and well draining. The herb prefers soil with a pH level ranging from 6.0 to 7.5. For a second harvest of basil leaves, plant the herb in very rich soil. Amend heavy clay soil by thoroughly mixing in organic matter such as compost or well-rotted manure and coarse sand. Amend sandy soils by adding generous amounts of compost into the soil and thoroughly mixing it with the existing soil. Soil pH testing kits are available at most garden centers or stores that have a gardening section. Adding sulfur or ammonium sulfate into the soil will lower the pH. Mixing bone meal, crushed oyster shells and hard wood ash will raise the pH level of the soil.
  
  

Water and Feeding

• Plant basil in a location where it will receive at least 6 to 8 hours of full sunlight. Water basil plants deeply once a week during dry spells. It is important that water leach through the soil to the bottom of the plant's root system. The soil of container-grown basil plants often dries out quickly and requires more frequent watering. Under watered plants usually recover once they receive adequate amounts of water. Fertilize the herb once at the beginning of the season and again half way through the growing season. Sparingly use a 5-10-5 fertilizer designated for use on edible plants.
  
  

Maintenance

• Bushy growth is encouraged through proper plant spacing and pinching. Grow basil plants at least 16 inches apart. Pinch the top of the center stem off once the plant is six weeks old. This encourages side branching and flowering. Cut off flower stems as they appear. Once basil begins to flower, it stops growing. Harvest basil leaves as needed or harvest the entire plant at one time. Leave at least six inches of the plant intact for a second harvest. Amend the soil if needed again and fertilize to promote new growth. Cover basil plants with sheets, newspapers or floating row covers when temperatures drop below 40 degrees F; basil does not tolerate cold.