Cinnamon Basil Basil can be sown indoors all year round. For outdoor cultivation, sow indoors from March to July and move outdoors as soon as temperatures exceed 20°C. A beautiful basil with contrasting violet stems, green leaves and lavender-coloured flowers which also look great in your border. The leaves have a clear cinnamon flavour and are often used in Arabic cuisine, especially in cakes and desserts.