Sweet Basil (Ocimum basilicum)

How much light does a Sweet Basil need?

Sweet basil prefers full sun, which the source describes as 6 or more hours of direct sunlight a day. It also grows reasonably well in part sun, at six hours of sun per day. Part shade is listed as an accepted condition, with full sun preferred. Indoors, most herbs need around eight hours of direct light each day. For basil, the indoor rating is direct sun, and it tolerates medium light.

• Light: Full sun and part shade (full sun preferred)^1,2

How often to water a Sweet Basil

The water rating for sweet basil is medium, and the low and high ends of the range are the same. The Plant Toolbox describes its moisture as moist. Medium is the only water level given, with no separate dry or wet tolerance. Soil drainage is listed as well drained and moist. Basil grows best in a rich, well-drained soil.

• Water: Medium¹

Best soil for a Sweet Basil

Sweet basil grows best in a rich, well-drained soil. The NC State Extension Plant Toolbox lists good drainage for this herb. The drainage record for sweet basil includes two values, well drained and moist. For soil pH, Clemson Cooperative Extension gives a range between 6.0 and 6.5. Basil's water rating is medium, which sits alongside its moist soil entry. A pH of 6.0 is the lowest value listed, and 6.5 is the highest.

• Soil drainage: Well drained and moist^1,2
• Soil pH: pH 6–6.5²

Hardiness and temperature

The hardiness entry for sweet basil covers USDA zones 10a to 10b. Zone 10a is the lowest zone given, and zone 10b is the highest. Sources list the plant as both an annual and a perennial. The plant type entry reads annual and herbaceous perennial. Zones 10a and 10b are the only ones the hardiness entry names.

• Hardiness: Zones 10a–10b¹

Fertilizing a Sweet Basil

Sweet basil needs light feeding rather than heavy feeding. The University of Minnesota Extension advises fertilizing sparingly. Its suggestion is a 5-10-5 commercial fertilizer, applied once or twice during the growing season. The fertilizer frequency entry reads light. Overall maintenance for sweet basil is rated low.

• Fertilizer: Light, once a year³

Pruning a Sweet Basil

Pinching is the pruning method named for sweet basil. You pinch the tips of long stems and any flower buds. Long stems and flower buds are the two targets named. The pruning type is listed as light shaping and deadheading. Pruning is listed alongside low overall maintenance for the plant.

• Pruning: Light shaping and Deadheading¹

How to plant a Sweet Basil

Sweet basil reaches about 2 ft (0.61 m) tall. Leave room for a spread of 0.3–1.2 ft (0.1–0.36 m). The hardiness entry covers USDA zones 10a to 10b. Plant it in full sun, with part shade as an accepted alternative. The soil pH range listed is 6.0 to 6.5. In the US, its native status is introduced in the lower 48, Hawaii and Puerto Rico.

• Hardiness: Zones 10a–10b¹

Winter care

Winter hardiness for sweet basil is recorded through USDA zones 10a and 10b. Zone 10a is the lower end of that range and zone 10b is the upper end. Sources list the plant as annual and as perennial. The plant type entry reads annual and herbaceous perennial. In the US, its status is introduced in the lower 48, Hawaii and Puerto Rico.

• Hardiness: Zones 10a–10b¹

When to plant Sweet Basil

Start seed indoors four to six weeks ahead of the outdoor planting time. The record states 4–6 weeks before the last spring frost. Maturity is listed as 42 days from seed.

• Start indoors: 4–6 weeks before last spring frost²

When and how to harvest Sweet Basil

Leaves are ready to pick about 6 weeks after planting. For drying, cut the leaves just before the flowers open. The maturity entry is 42 days from seed. Pinching flower buds is also listed as a pruning practice. Sweet basil grows at a rapid rate.

• Harvest: Pick leaves about 6 weeks after planting; for drying, cut leaves just before flowers open.⁴
• Days to maturity: 42 days from seed⁴

How to propagate a Sweet Basil

Three propagation methods are on record for sweet basil: seed, stem cuttings and division. The NC State Extension Plant Toolbox names seed. Seed is typically sown indoors four to six weeks ahead of the outdoor planting time. Division and stem cuttings are the other two methods listed. The maturity entry is 42 days from seed.

• Propagation: Seed, stem cuttings and division¹

Common problems

Japanese beetles and aphids are the pests recorded for sweet basil. Clemson Cooperative Extension also names slugs among the most common pests. NC State Extension calls aphids and Japanese beetles occasional insect problems. Fusarium wilt and downy mildew are the diseases listed. The NC State listing calls fusarium wilt and basil downy mildew disease problems.

• Common pests: japanese beetles and aphids^2,1
• Common diseases: fusarium wilt and downy mildew¹

Questions and answers

Is sweet basil toxic to cats or dogs?

The ASPCA lists sweet basil as non-toxic to cats and non-toxic to dogs. The NC State Extension Gardener Plant Toolbox also reads non-toxic for cats and for dogs. Each pet has its own entry, and both entries read the same.

How much sun does sweet basil need?

Sweet basil prefers full sun, described as 6 or more hours of direct sunlight a day. Clemson Cooperative Extension says it grows reasonably well in part sun, at six hours of sun per day. Indoors, most herbs need around eight hours of direct light each day.

When can I pick sweet basil leaves?

Leaves can be picked about 6 weeks after planting. The maturity entry is 42 days from seed. For drying, cut the leaves just before the flowers open.