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 – 3cm 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.