Clerodendrum Trichotomum: Growing The Harlequin Glorybower

Clerodendrum trichotomum [kler-oh-DEN-drum, try-KOH-toh-mum] is a flowering plant species, which is sometimes placed in the family Lamiaceae (the mint family) and sometimes classified as the member of the Verbenaceae family of plants and is native to China, Taiwan, Japan, Korea, and India.

The deciduous shrub with somewhat unkempt appearance was once believed to be the tree of good fortune. 

Blooms of the Harlequin Glorybower

The plant’s scientific name also reflects the same belief – the word Clerodendrum has originated from two Greek words: kleros meaning chance or luck and dendron meaning tree. 

While the belief was quite prevalent in pre-Linnaean Europe, it doesn’t seem to exist in modern times.  

The Clerodendrum trichotomum is more widely known with the following common names:

  • Harlequin glorybower
  • Glorytree
  • Peanut butter tree
  • Japanese Clethra

Clerodendrum Trichotomum Care

Size & Growth

Clerodendrum trichotomum typically grows as a large shrub. 

However, it can grow as a small tree for pots but needs to be trained. 

It can grow anywhere from 10’ to 20’ feet in both height and width, so make sure to give it plenty of growing space. 

Its large, soft, ovate, hairy, dark green leaves are known for the unique scent they release when rubbed or crushed. 

The smell is reminiscent of peanut butter, hence the common name peanut butter tree.

Flowering and Fragrance

Flowers of glorytree are one of the reasons behind its widespread cultivation in gardens. 

Borne on branching peduncles in loose clusters, the fragrant flowers are showy and have a sweet aroma and feature white petals within a green calyx. 

The calyx changes color from green to red as the bright blue fruits of the plant ripen. 

The bloom time starts from midsummer / late summer and lasts till fall.

Flowering is followed by the production of berry-like fruits, which are initially white, but become bright blue and then dark blue as they mature. 

The color is due to the presence of a unique blue pigment, named trichtomine after the plant. 

The fruits are also subtended by contrasting star-shaped red calyxes.

Light & Temperature

Japanese Clethra produces the best blooms and fruits when it is planted in full sun. 

However, it grows well in partial shade too. 

It also needs some sheltering from cold drying winds of the winter.

In very cold areas, the Clerodendrum trichotomum can die. 

Optionally, cut it back to the ground and treat it as an herbaceous perennial.

It is winter hardy to USDA zones 7 to 10.

Watering and Feeding

Clerodendrum trichotomum has moderate water requirements. 

Since it likes moist soil, provide enough water and do not let the soil dry out in the growing seasons. 

However, be careful to not overwater.

Soil & Transplanting

Harlequin glorybower grows best in loamy, organically rich, moist and well-draining soil. 

The plant will get damaged if the soil is not well-draining and remains waterlogged or soggy for a long period of time.

Grooming and Maintenance

Since the plant spreads to a wide area and is prone to suckering, it typically has an unkempt appearance. 

So, you will need some grooming to maintain it in good shape. 

Experts recommend removing suckers in the fall or spring.  

How to Propagate Harlequin Glorybower

Peanut butter tree is generally propagated by semi-hardwood cuttings in summer and via root cuttings in winter. 

While it can grow from seeds, it is a little frustrating because seeds do not always germinate and even when they do, they take a long time.

For successful seed germination, make sure to sow them in a greenhouse as soon as possible after collection and maintain the temperature at around 68° degrees Fahrenheit (20° C). 

Provided the right conditions, the seeds will germinate within 20 to 60 days. 

Wait for the seedlings to grow large enough to handle and then transfer to individual pots. 

However, let them stay in the greenhouse for the first winter, at least.

If propagating through root cuttings, take 2” to 3” inch long cuttings and plant them in a greenhouse, ideally in December.

Propagation of Harlequin glorybower is easiest by semi-hardwood cuttings as they can directly be planted into their permanent position.

Harlequin Glorybower Pest or Diseases

Glorytree can get affected by canker, galls, and leaf spots. 

The common pests, on the other hand, include:

Its beautiful and fragrant white flowers are highly attractive to butterflies, honeybees, hummingbirds, and many other pollinators.

According to a few sources, some parts of the plants, such as seeds, are poisonous if ingested.

Clerodendrum Trichotomum Uses

Prized for its fragrant white flowers and bright blue berries, C. trichotomum is mainly grown for ornamental purposes because it brings beautiful fall colors to gardens. 

It is also a great choice for shrub borders and is used as a specimen plant as well.

In some parts of the world, the roots and leaves of the Clerodendrum trichotomum are also used for medicinal purposes.

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