French or Common Thyme (Thymus vulgaris)
This subshrub is the thyme of the kitchen garden. One attractive cultivar for hanging baskets is silver thyme (T. vulgaris ‘Argenteus’).
Red Creeping Thyme (T. praecox subsp. britannicus)
The tiny leaves of this thyme have very little scent or flavor, so it is mostly used ornamentally as groundcover. The flowers are purple to mauve. Commonly sold cultivars include ‘Doone Valley’, ‘Kew’, and ‘Albus’.
Lemon Thyme (Thymus 5 citriodorus)
This spreading subshrub reaches a foot tall. It’s one of the best for cooking—and one of the most fragrant. Watch for variegated cultivars such as ‘Aureus’ (golden edges), ‘Golden King’ (mostly gold), and ‘Silver Queen’ (cream to light yellow edges).
Caraway Thyme (Thymus herba-barona)
This creeping thyme grows 2 to 5 inches tall with pink flowers. Caraway thyme comes from the islands of Corsica and Sardinia, so it can take higher levels of humidity and rain, making it a good candidate for Southern gardens.