Blue Butterfly Bush ( Clerodendrum ugandense): Two-Tone Sapphire Wings & Tropical Butterfly Shrub Guide

gardenathena

Oct 9

3 min read

Blue Butterfly Bush Photo by David J. Stang

Native to the sun-drenched, high-altitude thickets and tropical woodland margins of East Africa (primarily Uganda, Kenya, and Tanzania), Rotheca myricoides 'Ugandense' (widely known by its historic botanical synonym Clerodendrum ugandense) is one of the most exotic broadleaf evergreen ornamental shrubs in landscape design. Revered for its uniquely shaped two-tone blue blossoms that closely mimic hovering butterflies, its arching growth habit, and its extended blooming cycle, it serves as an eye-catching centerpiece in warm-climate borders and patio container gardens.

Each intricate flower features four pale sky-blue lateral petals paired with a striking, violet-sapphire lower lip. Long, gracefully curving stamens extend outward from the floral center, completing the illusion of a butterfly in mid-flight.

Alternative Names: Blue Butterfly Bush, Blue Glorybower, Butterfly Clerodendrum, Rotheca myricoides, Clerodendrum ugandense, Mavi Kelebek Çalısı (Turkish).

Introduction

Botanical Name: Rotheca myricoides 'Ugandense' (syn. Clerodendrum ugandense, Clerodendrum myricoides 'Ugandense'; Lamiaceae / Mint Family) — closely related to Glorybower (Clerodendrum), Rosemary (Salvia rosmarinus), and Lavender (Lavandula).
Native Habitat: East Africa (Uganda, Kenya, Tanzania).
Characteristics: A fast-growing, multi-stemmed, arching evergreen to semi-evergreen woody shrub that can behave as a scrambling vine when given vertical support. Reaches 1.5 to 3 meters in height with a spread of 1.5 to 2.5 meters in open landscapes (staying around 1 to 1.5 meters in container culture). Features ovate-lanceolate, dark green leaves that emit a slightly resinous scent when bruised. From early spring through late autumn (and year-round in frost-free greenhouses), terminal panicles yield clusters of 2–3 cm two-tone blue butterfly-shaped flowers.

Pros & Cons

Pros

Unrivaled Butterfly Floral Mimicry: Displays unique two-tone sky blue and violet-sapphire blossoms that mimic fluttering butterflies.
Continuous & Long Bloom Window: Produces an uninterrupted flush of flower clusters from early spring through the onset of winter frosts.
Versatile Growth Form: Functions beautifully as a specimen shrub, an informal hedge, or a scrambling container vine trained on a trellis.
Pollinator & Honeybee Magnet: Rich in nectar, the blooms attract bees, butterflies, and hummingbirds constantly throughout the warm season.

Cons

Frost & Freeze Sensitivity: Sustains severe dieback and foliage damage when exposed to freezing temperatures below -2°C to -3°C (26°F–28°F).
Unruly / Leggy Growth Without Pruning: Can become sprawling and irregular if left unpruned over multiple seasons.
Flower Drop Under Drought Stress: Drops flower buds and lower leaves rapidly if allowed to dry out completely during hot weather.
https://commons.wikimedia.org/wiki/User:Nova

Field Performance & Care Profile

Light Requirement: Full Sun to Partial Shade (Requires a minimum of 5–6 hours of direct daily sunlight for maximum flower yield and color vibrancy; light afternoon shade is beneficial in scorching desert climates).
Cold Hardiness: Tender (USDA Zones 9b–11). Sensitive to frost; must be overwintered indoors or in a sheltered greenhouse in cold continental zones.
Heat & Drought Tolerance: High heat/humidity tolerance, MODERATE-TO-LOW drought tolerance. Enjoys warm summer weather but demands consistently moist root zones.
Soil Requirements: Rich, organic, loose, well-draining loamy soils (pH 6.0 – 7.2).
Root System: Shallow-to-moderate, fibrous, adaptable woody root network.
Height & Spread: Reaches 1.5 to 3 meters in height and 1.5 to 2.5 meters in spread (100–150 cm in containers).
Watering: Moderate to High. Water regularly whenever the top 2–3 cm of soil feels dry during active growth; reduce watering frequency in winter.
Regional Adaptation: Perennial outdoors in frost-free Mediterranean, coastal, and subtropical zones; grown as a patio container shrub or greenhouse specimen in cold zones.
Lifespan: Long-lived broadleaf evergreen shrub.
Flower Characteristics: Two-tone blue flowers featuring pale sky-blue petals and a deep sapphire-violet lip with long arched stamens.
Bloom Period: Early spring through late autumn.
Care Level: Easy.

Popular Cultivars

Rotheca myricoides 'Ugandense': The classic, world-renowned selection celebrated for its intense sky-blue and deep sapphire butterfly blooms.
Rotheca serrata 'Blue Butterflies': A closely related species featuring similar butterfly-shaped floral architecture on larger, bolder foliage.
Mavi Kelebek Çalısı https://www.flickr.com/people/26698606@N03

Propagation Methods

Semi-Hardwood Cuttings (Easiest Method): Take 10–15 cm semi-hardwood stem cuttings in mid-summer or early autumn. Apply rooting hormone and place in a porous perlite-peat medium or water; roots establish within 2 to 3 weeks.
Propagation from Seed: Extract seeds from mature fleshy berries and sow in moist seed-starting mix at 20°C–24°C (68°F–75°F).

Pro Care Tips & Secrets

Perform Hard Pruning in Early Spring: Prune back older stems by one-third in early spring (February–March) to encourage dense basal branching. Because flowers form on new season growth, pruning significantly boosts flower production.
Feed with High-Potassium Fertilizers During Bloom: Apply potassium and phosphorus-rich organic fertilizers every 2–3 weeks during the flowering window to intensify the deep sapphire tones and maximize bloom count.
Provide Trellis Support in Patio Containers: When cultivating in large patio pots, insert a small bamboo pyramid or trellis inside the container to guide arching branches and maintain a neat, upright silhouette.