Clerodendrum trichotomum

Clerodendron trichotomum, also known as the luck tree, clergy tree, or turquoise tree, is a bush with an exotic appearance and exceptional fragrant autumnal flowering. It is adorned with a profusion of turquoise berries set in a bright pink casing. This shrub requires very little maintenance and is rarely sick.

It forms a large, airy shrub with a rounded shape, reaching 3 m to 4 m (9.8 ft to 13.1 ft) in height and 2 m to 3 m (6.6 ft to 9.8 ft) in width. If you take care to trim the lower branches, it can form a small tree on a stem, up to 5 m to 6 m (16.4 ft to 19.7 ft) tall. The young branches are pubescent, which distinguishes it from the other hardy species of the genus Clerodendrum bungei.

Its large opposite, deciduous leaves are ovate in shape, ending in a point and strongly veined. The leaves are of a medium green colour, with a downy underside. Larger in young subjects, they can measure 17 cm to 25 cm (6.7 in to 9.8 in) long by 5 cm to 15 cm (2 in to 5.9 in) wide and have a fine serration. When crushed, they emit a curious peanut-like fragrance, which allows immediate identification. The leaves appear late in spring and are not particularly decorative in autumn as they fall at the first frost, but the shrub offers many other advantages.

In August-September, the luck tree produces a rich and abundant flowering with an almost exotic appearance. The small white star-shaped flowers, carried by an elongated angular calyx washed with purple, are gathered in panicles about 15 cm to 20 cm (5.9 in to 7.9 in) wide, and are highly fragrant. The corolla forms a tube terminated by 5 petals from which sprout 4 stamens and a style, like all members of the Lamiaceae family (formerly Verbenaceae).

In autumn, the shrub is adorned with a profusion of berries, no larger than currants, but of an intense turquoise colour, enclosed in a bright red calyx. This fruiting is more or less regular depending on the year and the climate.

Hardy (-15° C (5° F)) and easy to grow, it thrives in full sun or partial shade, in any well-draining and moist soil without excessive limestone. It only dislikes heavy soils that are waterlogged in winter and excessive heat in summer. Like the tree angelica (Aralia elata), its roots can sometimes produce suckers, but this species suckers much less than Clerodendrum bungei. Its growth is rapid and it has a lifespan of over 30 years. It is sometimes attacked by scale insects.

To enjoy its fragrance, consider planting close to a pathway or near to the home. In a small garden, plant it as a standalone specimen to create a small shade tree. It will enhance the area with its intense fragrance and unique flowering from the end of August to October, when the majority of garden plants are finishing their flowering. However, avoid parking your car underneath it as the fruits stain and attract birds. The shrub also makes an ideal flowering hedge plant and is popular with birds that delight in the fruits. Pair it with shrubs with beautiful autumn colours such as forsythia, Japanese quince, witch hazel, amelanchier, Japanese maple or Persian ironwood, a climbing vine with sumptuous foliage in autumn. 

Plant late-flowering perennials such as Helianthus microcephalus, Heliopsis, asters in the foreground.

It is a tolerant plant in terms of soil, as well as cold once established. It will bring an exotic touch to a free hedge or shrub bed.

The genus name Clerodendrum comes from the Greek kleros which means "clergy" and dendrum which means "tree". This genus includes more than 400 species, mostly tropical (tropical Africa and South Asia), consisting of trees, shrubs, climbers, and herbaceous plants. The name "clergy tree" was given to recall their use in Indo-Malay religious ceremonies. The species populates the woods and thickets of Japan, Korea, eastern China, and the Philippines, up to 2300 m (7545.9 ft) in altitude. The variety fargesii is a slightly hardier form (-20° C (-4° F)) from western China, brought to the Vilmorin Arboretum by Father Farges in 1898. Its young leaves are bronze, the calyx green, the branches and leaves glabrous, but the fruits are less vibrant than in the type.