Genovese Basil

What it is. Genovese is a cultivar of sweet basil (Ocimum basilicum), a mint-family herb. It has larger leaves than traditional basil and grows about 2 feet (60 cm) tall. It is regarded as one of the best types for pesto and garlic dishes, with dark green leaves and a slow tendency to bolt. Basil is generally grown as a tender plant that is damaged by frost.

Growing notes. Most sources describe sweet basil in general rather than this cultivar, so the growing advice below applies to basil as a whole.

Sowing. Sow seeds outdoors only after all danger of frost has passed. Sow the seeds about 1/8 inch (0.3 cm) deep and cover them lightly with soil; another guide says ¼ inch (0.6 cm) deep. If you start seeds indoors, begin 4 to 5 weeks before the last frost date.

Germination. Seeds sprout in about 10 to 14 days when the soil is 75 to 85°F (24 to 29°C). Other guides give 5 to 7 days, 1 to 2 weeks, or 5 to 10 days at 65 to 70°F (18 to 21°C).

Spacing. Thin the seedlings until the plants stand 12 inches (30 cm) apart. One guide suggests 12 to 18 inches (30 to 46 cm) apart for good airflow.

Light and containers. Plant in full sun, where the plant gets 6 or more hours of direct sun each day. Basil is well-suited to containers and can also be grown indoors on a sunny windowsill.

Watering. Water regularly, supplying about 1½ inches (3.8 cm) of water per week. Keep the soil moist but well-drained.

Feeding. Avoid heavy nitrogen fertilizer, because too much nitrogen affects the flavor.

Pinching. Pinch the stem tips to encourage a bushy plant with more leaves. Pinch off flower buds as soon as they form.

Downy mildew. Basil downy mildew is a serious disease, and the Genovese cultivar is one of the most susceptible varieties. Resistant cultivars include ‘Obsession’, ‘Devotion’, ‘Prospera’, and ‘Amazel’. Avoid crowding the plants and avoid overhead watering to reduce the risk.

Other problems. Aphids and Japanese beetles are occasional insect pests, and Fusarium wilt can affect basil.

Harvest when flower buds have started to form but before they open, since the flavor fades after the seed forms. Leaves can be picked about 6 weeks after planting.

Keep freshly cut stems in a jar of water at room temperature, away from direct sun. Putting basil in the refrigerator can leave the leaves discolored. To freeze basil, chop the leaves with some water and freeze them in ice cube trays.

Basil is listed as non-toxic to both cats and dogs.