What Fertilizers Do Basil Plants Need?

Fertilizing

• Under ideal soil conditions, basil plants need little to no fertilizer. A moist, though not sopping wet, soil that's well mulched and a bit sandy is preferable. A pH range of 5.5 to 8 typically provides all the essential nutrients the plant needs. If the soil lacks these nutrients, however, add fertilizer.

Type

• If you determine the basil plant needs fertilizer, use one that's granular, slow-acting and water-soluble. In some cases, a diluted liquid fertilizer produces desirable results. A granular fertilizer used on basil plants needs an NPK (nitrogen, phosphorous and potassium) rating of 10-10-10 or 10-10-12. Organic fertilizers produce favorable results when applied to basil plants.

How and When

• Apply fertilizer to basil plants once at the initial planting, and additionally every four to six weeks. For granular fertilizers, apply a small handful of the granules to the area around the base of the plant and water them in, ensuring none of the granules settle on the plant leaves. If you have a large plot of basil plants, use 1 1/2 lbs. granular fertilizer per every 100 square feet of plants (for containers, a small handful of granules will suffice). Apply liquid fertilizers and along with the regular watering.

Tips

• Over-fertilizing a basil plant leads to excessive leaf growth and less flavorful harvested basil. Also, over-fertilizing leaves the basil plant more prone to fungal and mold infection. Never apply fertilizer at temperatures below 60 degrees F, as this leads to spur fungal and mold growth. Avoid fast-release and artificial, synthetic or inorganic fertilizers, as they produce overly large leaves that lack in flavor compared to their smaller counterparts.