All About Basil

The aromatic oils in basil (Ocimum basilicum) release the spicy fragrance of cinnamon, anise, clove, or lemon.

This easy-to-grow annual herb has green or purple leaves, and some cultivars have ruffled or serrated edges. All are attractive planted in containers, perennial beds, and kitchen gardens. Basil adds flavor to pasta, pesto, jams, vinegars, salads, and teas. Originally from Asia and Africa, this herb needs plenty of warm weather-the slightest frost damages it.

Common name: Basil, sweet basil
Botanical names: Ocimum basilicum
Plant type: Herb
Height: 8 to 36 inches
Zones: Annual good for Zones 3 to 11
Family: Lamiaceae (Mint)

Growing conditions
Sun: Full sun
Soil: Well-drained soil amended with organic matter
Moisture: Evenly moist

Care
Mulch: Apply a thin layer of compost to conserve moisture.
Fertilizer: None required unless the soil is very poor
Pruning: Remove flower heads and pinch growing tips to encourage bushy growth and maintain best flavor in the leaves.

Cultivars

  • ‘Dark Opal' has dark purple leaves. Garnish Rice and salads with this basil for a colorful accent. Grows 12 to 24 inches tall.
  • ‘Cinnamon' has serrated green leaves with a spicy tang and pink to purple flowers. Grows 18 to 30 inches tall.
  • ‘Purple Ruffles' has curled, purple leaves with a clove scent. An All-America Selections winner, it's an attractive contrast to green foliage in the perennial border. Grows 12 to 24 inches tall.
  • ‘Siam Queen' has green leaves with a licorice fragrance. Highly ornamental, this All-America Selections winner has large violet flowers that contrast with the green foliage. Grows 30 inches tall.
  • ‘Spicy Globe' has tiny, green leaves and is slow to go to seed. It has a distinct globe shape and grows 6 inches tall.

Garden notes
Because basil is temperature-sensitive, plant out of harsh winds and in warm soil.
Plant successively to have a good crop all summer.
Basil easily cross-pollinates with other basil plants, so keep cultivars separated by several feet so plants grow true to seed.
Basil leaves are difficult to dry. Instead, wash and dry leaves, cover each side with oil to keep them from sticking together, and freeze in a freezer bag.

Pests
Slugs, white fly, and red spider mites may attack basil.
Damping-off may occur during germination when soil is cool.
Fusarium wilt causes leaf drop.

Propagation
In early spring, sow seeds indoors four to six weeks before last frost, then transplant outside in a sheltered spot when danger of frost is gone. Place plants about 6 inches apart.
In regions where nighttime temperatures stay above 55ºF, plant seeds directly in the soil.

All in the family
Examples of the Lamiaceae family include sage (Salvia spp.), thyme (Thymus spp.), English lavender (Lavandula angustifolia), mint (Mentha spp.), catmint (Nepeta spp.), and oregano (Origanum spp.). The stems are square or angled, and they have aromatic leaves.