Dark Opal Basil is an attractive, flowering herb that looks great and tastes great as well. The flowers are lilac to burgundy colored, and sit atop deep red leaves. The plants themselves form a bushy growth habit, ranging in height from 12 to 18 inches tall. The flowers will attract an array of beneficial insects to the garden, and can also be used in insectaries and butterfly gardens as well. The flowers can be snipped and added to drinks, desserts and salads to spruce things up. Dark Opal Basil is categorized as an annual flowering herb. Annuals such as this, will grow within a single growing season, producing leaves, flowers and seeds by the end of the Autumn season. These plants are often established directly in the garden, or in pots and containers as well.