Thai Basil Ocimum basilicum

Sweet basil is an herb in the Lamiaceae (mint) family and native to the tropical regions of Africa and Asia. Thai and Genovese basil are cultivars of this plant. The fragrant edible leaves are great in soups, stews, and other meat dishes. 

Sweet basil prefers full sun and moist, well-drained soils. It can be grown from seed or is easily transplanted and should be done so after the last frost. Prune by pinching the tips of long stems and any flower buds. This promotes a branching, bushy form.

Sweet basil cultivars with showy purple foliage are often used as ornamentals and are perfect for containers. Plant in a bed or window box to create contrasting colored foliage. Miniature varieties are also available, which are great for mass plantings along the edge of flower beds. 

Insects, Diseases, and Other Plant Problems: Aphids and Japanese beetles are occasional insect problems. Fusarium wilt and basil downy mildew are disease problems. There are several cultivars that are resistant to basil downy mildew.

Extension Master Gardener℠ volunteers from across the state of North Carolina conducted a trial of resistance to basil downy mildew and leaf flavor. They evaluated plant performance and taste using the cultivar 'Genovese' as the standard of reference. They found clear winners that were resistant to basil downy mildew and performed well in the garden and in the kitchen. The top cultivars were: 

‘Prospera’ – This cultivar was the overall favorite among the mildew-resistant cultivars. Because of its taller stature, it required staking in some gardens, and some volunteers reported stems breaking during storms.

‘Rutgers Passion’ – This cultivar performed well in terms of its color, aroma, plant vigor, and good branching habit. 

‘Rutgers Obsession’ – This cultivar was highly rated for its color and compact growth habit. It exhibited strong resistance to basil downy mildew and was the highest rated variety in taste tests.

For more information about the basil trials click here. 

VIDEO Created by Elisabeth Meyer for "Vegetables, Herbs, Fruits, and Nuts" a plant identification course offered in partnership with Longwood Gardens.