Plant Portraits: Osmanthus fragrans (Guìhuā (桂花) or Sweet Olive)

It is customary in Hong Kong for 5 star hotels to have a house fragrance, pumped into lobbies in heady clouds and sold at great expense in the gift shop. However, it’s not often one steps out of a car onto the street in China to be greeted by a similar olfactory experience. In fact quite the reverse. But in Hangzhou, one of northern China’s more elegant and green cities, the autumn air is now delicately infused with the smell of ripe peaches. The plant responsible for this fruity scent is Osmanthus fragrans, known locally as guìhuā (桂花) and in the UK as sweet or fragrant olive. Whilst not sophisticated, the scent is light and youthful, reminiscent of the fragrance used in apricot and peach-scented cosmetics.

The flowering of sweet olive is much celebrated in China, with Hangzhou and Suzhou selecting it as their city flower. Another city, Guilin (translated as ‘forest of sweet osmanthus’) is named after the numerous sweet olives which can be found there. It’s no wonder then that Osmanthus fragrans is used so extensively in China for public landscaping. Even moving at speed along the expressways of Taizhou, the pale orange flowers of Osmanthus fragrans var. aurantiacus are unmistakable, smothering the neatly trimmed bushes at the roadside.

Osmanthus fragrans, October 2013

Osmanthus fragrans (photo Apalachee Hills landscape)

All osmanthus species are related to the olive, so the common name is appropriate. For those who, like me, enjoy a bit of latin, the name osmanthus is derived from the Greek ‘osma’, meaning fragrant, and ‘anthos’, meaning flower. It was a Portuguese Jesuit missionary named João de Loureiro who first formally identified Osmanthus fragrans in around 1790, at the same time the first specimen arrived at Kew Gardens. Having been collected in South China the plant did not take well to the English weather and failed to flower well. Today, a specimen can be found in the more clement surroundings of the temperate house at Kew.

Although relatively new to British gardens, sweet olives have been cultivated in China for over 2,500 years, and are still an important part of the culture there. The flowers, in Chinese guì huā 桂花 (literally translated as ‘cinnamon flower’), can be used to make teas (guì huā chá 桂花茶), jams, soups, liqueurs, deserts, confectionery and medicines – a little like our own delicate elderflowers. My colleagues in China told me about a particularly delicious desert made by stuffing a lotus root full of of sticky rice and glazing it with osmanthus jam. In Chinese herbal medicine a tea made from sweet olive bark is used to treat boils and carbuncles, whilst the essential oil is considered to have insect-repelling properties.

Osmanthus fragrans var aurantiacus

Osmanthus fragrans var. aurantiacus (photo Il Giardino)

Osmanthus fragrans naturally occurs in the Eastern Himalaya, through China and into Taiwan and southern Japan, but is now widely planted throughout the warmer parts of Asia, the USA and Europe. In the UK, sweet olive is considered slightly tender, tolerating short spells below 0°C but preferring temperatures a little more on the balmy side. In the south of England a warm wall might offer enough winter protection, otherwise a cool conservatory might be a better choice. The fragrance in a confined space would be superb. Sweet olive is not a small shrub or tree, reaching 12 metres in time. The leaves are green to slightly silvered and the flowers white, cream or pale yellow and insignificant – similar in some ways to Elaeagnus ‘Quicksilver’ . For more of a showy plant, track down the the orange-flowered variant, Osmanthus fragrans var. aurantiacus, a plant your neighbours are very unlikely to have. The flowers’ scent is especially powerful in the evening, so plant close to doors, windows and terraces to get the best from them in late summer and autumn.

The scent that greats me on my return to London is rain on tarmac and damp leaves. Fragrances just as evocative, but that would not fetch a great sum in the hotel gift shops of Hong Kong. I look forward to returning to Hangzhou again next year to experience this scent again, and perhaps track down a pot of osmanthus jam.

The white form of Osmanthus fragrans is available from Burncoose Nurseries in Cornwall.

Osmanthus fragrans