Hoya globulosa (Cao Bang) – A Rare Vietnamese Form with Pale Blooms
Hoya globulosa (Cao Bang) is a regionally distinct form of Hoya globulosa Hook.fil., collected from the cooler highlands of northern Vietnam. This slow-growing climber stands out with fuzzy straw-colored flowers, soft pink coronas, and leathery, oblong leaves. It’s more tolerant of mild indoor temperatures than many Hoyas and adapts well to typical household humidity — a great choice for collectors wanting something unusual but easy to grow.
What Makes Hoya globulosa (Cao Bang) Unique

 
Fuzzy Pale Flowers: Cream to straw-colored corollas with pink coronal lobes, forming globe-like umbels of 10 – 20 fragrant blooms.
 
Textured Foliage: Thick, glossy, dark green leaves with rounded bases and tapering points — a sturdy contrast to the soft flowers.
 
Climbing Growth: Can trail from baskets or climb a moss pole. Naturally slow but steady in favorable conditions.
 
Cool-Tolerant Origin: Native to Cao Bang Province, where humid forests offer filtered light and mild temperatures year-round.

Light, Water, and Humidity Preferences

 
Light: Bright, indirect light is ideal. A few hours of morning sun are fine, but avoid harsh midday exposure.
 
Water: Let the top 2 – 3 cm of substrate dry before watering. Always use a well-draining mix to prevent soggy roots.
 
Humidity: Thrives in 60 – 80%, but adapts to normal indoor levels if airflow and hydration stay consistent.
 
Temperature: Prefers 18 – 25 °C. Unlike many tropical Hoyas, it tolerates short drops to 15 °C without stress.

Recommended Substrate and Feeding Routine

 
Potting Mix: Use a chunky epiphytic blend of orchid bark, perlite, and coco coir or sphagnum moss.
 
Containers: Choose breathable pots or baskets with good drainage. Slight root restriction encourages flowering.
 
Fertilizing: Apply a balanced liquid fertilizer every 4 – 6 weeks if the plant is actively growing. Pause if light is low.

Common Care Issues and How to Fix Them

 
Yellow Leaves: Usually a sign of excess moisture or poor lighting. Improve drainage and move to a brighter spot.
 
Leaf Curl or Browning Tips: Often due to inconsistent watering or dry air. Boost humidity and check moisture levels regularly.
 
Pests: Watch for mealybugs and spider mites. Wipe leaves and treat with neem oil or insecticidal soap as needed.
 
Fungal Spots: Prevent by maintaining airflow and avoiding water sitting on leaves. Use a fungicide only if necessary.

Tips for Display and Propagation

 
Support Vines: Use a moss pole, bamboo trellis, or let stems trail loosely from a shelf or basket.
 
Propagation: Take stem cuttings and root in water or damp moss-perlite mix. Let cut ends callus before planting.
 
Cleaning: Gently wipe leaves with a soft cloth to remove dust and support healthy photosynthesis.

Toxicity and Handling
Like most Hoyas, Hoya globulosa (Cao Bang) is generally considered non-toxic but contains a milky sap that may irritate sensitive skin or mouths. Keep out of reach of pets and small children.
Etymology and Botanical Background
The genus Hoya honors English botanist Thomas Hoy. The species name globulosa refers to its round, globe-like flower umbels. “Cao Bang” describes the plant’s collection origin in northern Vietnam — it is not a formal botanical variety but an informally recognized regional form.
Taxonomic Citation
Botanical name: Hoya globulosa Hook.fil.

Published in: Hook. fil. (1882), Gardeners' Chronicle I: 732
Bring Hoya globulosa (Cao Bang) into Your Collection
This uncommon Hoya offers a more temperate-friendly take on the classic fuzzy globulosa bloom. Order now and enjoy its subtle charm, unique texture, and rare Vietnamese origin — perfect for any serious plant enthusiast.