Mammoth Basil is vigorous annual that grows 46-61 cm (18-24") high and 40-45 cm (16-18") wide. It produces huge, slightly ruffled shiny, green leaves, twice as large as other Italian basils, deserving of its name, Lettuce-leaf basil. The flavor is similar to sweet basils' flavor. Give plenty of space per plant, 15-20 cm (6-8") so the leaves can dry out after wet spells. Use fresh or dried leaves. Fully mature leaves have a sweet mild taste and smell. Pruning growing tips makes for bushier plants.
Start seeds indoors 6-8 weeks before the last expected frost or sow seeds outdoors after the last frost. Basil requires well-draining soil that is rich in organic matter, and it prefers full sun but can also tolerate partial shade. Sow seeds 1cm (½”) deep and 15-20cm (6-8”) apart. Keep the soil consistently moist until the seedlings emerge, which can take 5-10 days. Once the seedlings have emerged, water them deeply once a week, and allow the soil to dry slightly before watering again. Pinch the growing tips regularly to encourage bushy growth, and harvest leaves regularly to encourage continued growth. Basil can also be grown in containers, which can be brought indoors before the first frost to prolong the growing season. Basil can be harvested once it has reached 15-20cm (6-8”) in height, and regular harvesting will encourage continued growth.
Soil Conditions: Well-draining soil that is rich in organic matter. Planting Depth: Sow seeds 1cm (½”) deep. Germination: 5-10 days. Height at Maturity: 30-60cm (12-24”) tall. Days to Maturity: 60-90 days. Watering: Water deeply once a week, and allow the soil to dry slightly before watering again. Sun/Shade: Full sun, but can tolerate partial shade. Spacing after Thinning: Space seedlings 15-20cm (6-8”) apart.