Over fertilising basil sacrifices flavour for growth. If more than one harvest is made, a side-dressing with 16 to 33 kilograms N per hectare shortly after the first or second cutting is recommended. Pest control in herb production, both greenhouse and field production, is often hampered by a lack of pest control products. There are several diseases that may infest basil plants, including Fusarium wilt. Plants should be carefully monitored for the presence of insects and diseases.
Weed control is critical because competition with weeds decreases the quality of basil leaves.
To keep weed populations low, high plant populations, shallow cultivation, or mulching should be used. Leaf cuttings of basil may be harvested from one to five times per season, depending on the area involved and the length of the growing season. The basil should be refrigerated as soon as possible after cutting, preferably in the field. Harvesting of basil should occur in the morning after the dew has left the plants but before the heat of the day. A sickle-bar mower with adjustable cutting height is commonly used for harvesting large plantings for dried basil production.