Clerodendrum (Clerodendrum trichotomum)
Discover Clerodendrum trichotomum, a deciduous shrub known for its showy, fragrant white flowers blooming late summer into fall.
Complete Plant Information
Overview
Clerodendrum trichotomum, commonly known as Harlequin glorybower, is a striking deciduous shrub or small tree native to Eastern Asia. It provides substantial late-season interest through its uniquely appealing white flowers and subsequent bright blue fruits contrasted against fleshy red calyces. This plant, a type of Clerodendrum, is prized for its fragrance and ornamental display happening when many other garden specimens are fading.
While it can grow up to 20 feet tall, Clerodendrum trichotomum often presents as a coarse, suckering shrub needing management to maintain a desired shape. Its foliage is also highly memorable, producing a distinct aroma reminiscent of peanut butter when bruised, earning it the nickname “peanut butter tree.” For gardeners in suitable climates, the combination of summer bloom and colorful fruit makes this Clerodendrum an indispensable specimen.
Successful cultivation of this sometimes unkempt wonder requires attention to hardiness zones as reliability decreases in cooler marginal areas. When sited properly, the Clerodendrum trichotomum offers powerful visual impact coupled with strong ornamental textures throughout late summer and into the fall season.
Fast Facts
- Plant Family: Lamiaceae
- Plant Type: Deciduous shrub
- Native Range: Eastern Asia
- Hardiness Zones: USDA Zones 7-10
- Size at Maturity:
- Height: 10-20 ft
- Spread: 10-20 ft
- Bloom Time: July to September
- Bloom Description: White
- Sun Exposure: Full sun to part shade
- Water Needs: Medium
- Maintenance Level: Medium
How to Grow
Planting Clerodendrum trichotomum is best done in spring, allowing adequate time for root establishment before winter stress. It thrives in organically rich, well-drained soils. Ensure the selected location receives full sun to light part shade; while it tolerates shade, flowering and overall vigor will be significantly reduced.
Maintaining consistent moisture is key, as the plant requires medium water needs, especially during establishment and hot periods. Fertilization is generally not crucial if the soil is rich, but a balanced, slow-release feed in early spring can promote robust growth. Due to its tendency to sucker, pruning may be necessary to control spread or train a favored central leader if a tree form of Clerodendrum is desired.
For gardeners in the cooler edges of its range, winter preparation is vital. Plants in St. Louis, for example, are not reliably hardy. If attempting cultivation in marginal areas, site the shrub in a protected location, perhaps near a warm wall, and apply a thick layer of insulating winter mulch around the base after the ground freezes to protect the root zone.
Landscape Uses
When winter hardy, Clerodendrum trichotomum serves beautifully as a dramatic accent in shrub borders or along woodland margins where its large leaves and late blooms can be appreciated. Where the plant spreads vigorously via suckers, it can be effectively utilized as an informal screen or a natural-looking hedge, providing height and seasonal interest. Some gardeners allow it to naturalize slightly in large garden settings, embracing its sometimes unkempt habit while appreciating the low maintenance once established.
In more formal designs, gardeners should restrict its suckering tendencies through diligent removal of new shoots emerging outside the designated area. Due to its substantial size potential (up to 20 feet), ensure adequate space is given to prevent overcrowding. Consider pairing the Clerodendrum with plants that offer contrasting foilage textures or earlier bloom times to extend garden interest throughout the season.
Standout Features
Flower Qualities
- Showy
- Fragrant
Fruit Qualities
- Showy
Noteworthy Characteristics
Clerodendrum trichotomum, native to China and Japan, is a coarse, sometimes unkempt, deciduous shrub or small tree that grows 10-20’ tall. It is most often seen as a suckering shrub, though it must be trained to grow as a tree. As an ornamental, this shrub is perhaps best noted for its late summer flowers, showy fruit, and malodorous foliage, which releases a peanut butter-like aroma when bruised. Tubular, fragrant, white flowers appear in large cymes, followed by small, bright blue fruits subtended by fleshy red calyces.
Tolerances
(No data specified)
Potential Problems
This plant rarely suffers from serious insect or disease issues, making it a relatively robust choice for the dedicated gardener. Its primary management concern revolves around controlling its aggressive, suckering habit rather than pest control. If foliage odor is not desirable near high-traffic summer seating areas, plant the Clerodendrum further away. Its lack of reliable winter hardiness in northern locales dictates the need for careful siting and winter protection.
Frequently Asked Questions
What hardiness zones is Clerodendrum trichotomum suitable for?
Clerodendrum trichotomum is reliably hardy in USDA Zones 7 through 10, though gardeners in Zone 7 should be prepared to offer winter protection.
How large does Clerodendrum grow?
This species typically reaches a height and spread between 10 and 20 feet at maturity, often developing into a multi-stemmed shrub.
What sun exposure does Clerodendrum need?
For the best performance, including rich bloom production, Clerodendrum trichotomum requires full sun to partial shade conditions.
When does Clerodendrum bloom?
The striking flowers of Clerodendrum bloom late in the season, typically from July through September, displaying beautiful white coloration.
Conclusion
The unique late-season floral display, coupled with the visually arresting combination of blue fruit and red calyx, secures the value of Clerodendrum trichotomum in the landscape. Although sometimes challenging due to its vigorous, suckering habit and variable winter hardiness, this Clerodendrum offers significant ornamental payoff. Before planting, confirm your local hardiness zone and amend your soil to be organically rich for the best chance of success with this fascinating shrub.
Companion Planting
Choosing appropriate neighbors enhances the appeal of Clerodendrum trichotomum while managing its size. Companion plants should generally share similar requirements for medium water and sun tolerance. Consider pairing it with late-blooming Hydrangeas or robust perennial grasses that will contrast nicely with the large leaves of the Clerodendrum during the late summer season.
Since this plant achieves significant height, place shorter, shade-tolerant groundcovers or annuals beneath it to fill in the base, especially in partial sun locations. Avoid planting highly sensitive or formal specimens immediately adjacent, as the suckering habit of the Clerodendrum may require frequent intervention nearby.
Seasonal Care Calendar
For optimal health, focus on soil improvement and monitoring during the growing season. In Early Spring, this is the ideal time to apply a balanced fertilizer if needed and cut back any winter-damaged stems before new growth begins. Summer requires keeping the soil consistently moist, checking water needs, especially during dry spells, and actively pruning stray suckers if the shrub form is becoming unruly.
As Fall approaches, enjoy the transition from the white flowers to the persistent, showy blue and red fruit display. Do not prune heavily at this time; allow the structure to remain for winter interest. In late Fall, if grown near the edge of Zone 7, apply a heavy layer of mulch after the first hard frost protection around the root crown.
