Heliotropium arborescens, commonly known as the Garden Heliotrope or Cherry Pie Plant, is a shrub that originated in Peru, South America. It is an attractive plant with dark green textured foliage and deep purple, lilac or white flowers, and it is particularly noted for its blooms' distinctive sweet and fruity scent, which is just like cherry pie.
The plant has been known and loved in cultivation since the 1750s, and even inspired artists, poets and poetry. Emily Dickinson almost certainly grew Heliotrope in her famous garden1 and a perfume created to evoke the flowers' fragrance persuaded Arthur Symons to write 'White Heliotrope' in the 19th Century. In the 20th Century, Cicely Mary Barker included a Heliotrope Fairy in her 'Flower Fairies' series of paintings and poems.
How to Grow Heliotropes
In warm climates, where winter temperatures stay well above freezing, Heliotropes can sometimes be seen formed into hedges, as they are perennial2 plants that grow to a height of over a metre. In cooler climates, they are generally grown as annuals3 instead, as temperatures below 2°C (36°F) will kill them - they will grow to about 45cm (18in) in height and spread during the growing season.
Cherry Pie Plants are often available for purchase from garden centres, either as established plants when they are in flower, or in seed form. They are fairly easy to propagate from cuttings too, so you should never have a shortage of Heliotropes if you want them in your garden every summer. They like a sunny spot and sandy soil, and need to be regularly watered (but not waterlogged). Feeding them every six weeks with general-purpose fertilizer and deadheading the faded blooms will encourage the plants to flower from May to September4, or even into October if the Autumn is mild.
To grow Heliotropes from seed, sow the seeds in February or March5, and keep them in a heated greenhouse or propagator, or indoors on a sunny windowsill. It may take more than a month for the seeds to germinate and start growing, so patience is required. When the seedlings are big enough to handle, they can be transplanted into pots and kept in the greenhouse until all danger of frost is past. They can then be planted in the garden.
To propagate the plants from cuttings, in Autumn cut non-flowering stems about 5-7cm (2-3in) long from the Heliotropes in your garden. Insert the stems into a plant pot filled with sandy soil and then keep the pot indoors over winter in a sunny place, ensuring the compost stays moist. The successful cuttings can be planted out in the garden the following Spring, again when all danger of frost is past.
Heliotropes in the Garden
The cherry pie scent is also attractive to bees, butterflies and other insects, who are rewarded with plenty of nectar when they find the Heliotrope flowers. However, all parts of the plant are poisonous6 - even though the velvety flowers look lovely and the scent may seem delicious, the plant is not good enough to eat.
There are many varieties of Heliotrope arborescens, of various colours and growth habits, including 'White Queen' and 'Marine'. Two of them have Awards of Garden Merit7 from the Royal Horticultural Society - 'Chatsworth' has deep purple flowers and a strong scent, and 'Princess Marina' is a good bushy plant with violet-purple blooms.
To maximise the value of the fragrance of your Garden Heliotropes, plant them in containers near a doorway, by a well-used path, or include them in a hanging basket, so that you can enjoy the evocative scent every day in summer.