Heliotrope is an aromatic shrub native to Peru. It is a favorite in old fashioned gardens, moon gardens, and cottage gardens, and it does well in a variety of temperate to tropical climates, although it is extremely frost tender. While heliotrope is sometimes treated as a rather old fashioned flower, many garden supply stores carry seedlings for gardeners who wish to plant them, and there are several different cultivars to choose from, for gardeners who want to play with new varieties.
Classically, heliotrope has dark green foliage which is deeply crinkled, with lush dark purple flowers which grow in small clusters. The plant has a very strong aroma which is sometimes compared to vanilla, and the scent tends to come out more when the plant is stressed by heat and lack of water. Other cultivars may have white, pink, or pale purple flowers, and foliage which varies slightly in color and size.
This shrub is treated as an annual in many more northern climates, because it cannot last through the winter. Sometimes heliotrope can surprise a gardener, however. If the plant is pruned back and mulched, it may last through the winter and leaf out in the spring, even if the winter weather was frosty or cold. Gardeners in marginal zones can protect their heliotropes by covering them on cold nights so that they will make it through the winter.
Also known as the turnsole or cherry pie plant, this shrub has another interesting trait beyond the distinctive scent: it turns to track the sun over the course of the day. During the evening, heliotropes will also reorient themselves in an easterly direction so that they are ready for sunrise, and in hot climates, the flowers may remain closed during the day and open up at night. This trait can make the plant well suited to moonlight and night gardens, because it will release ample amounts of its intoxicating scent at the times when people wander the garden.
This plant needs lots of nitrogen rich fertilizer to grow well, and it can be grown in the ground or in containers. Gardeners should also be aware that heliotrope needs to be routinely trimmed or pinched, or it will develop a leggy and top heavy appearance. Despite the tempting scent, the plant contains toxins which can be dangerous to people and pets, and it may be necessary to secure heliotrope behind a fence in a garden where curious pets like to wander and nibble.