Hoya Sungwookii (formerly Hon Thom)

🌿 Hoya sungwookii, formerly known as Hoya Hon Thom, is a rare vining species in the Apocynaceae family that comes from limestone areas in Thailand and Vietnam. This tropical epiphyte grows naturally on trees and rocks in humid forest environments, producing thick succulent leaves and stunning fragrant flower clusters. It's considered an intermediate-level plant, requiring attention to watering and humidity but rewarding growers with its unique characteristics. Fun fact: this Hoya was only recently described and officially named in 2015, making it one of the newer additions to the Hoya genus.
FOLIAGE AND GROWTH HABIT
This Hoya grows as a climbing or trailing vine with thick, succulent leaves that store water in their tissues. The leaves are oval to lance-shaped, with a leathery texture and deep green colour that sometimes shows lighter veining. New growth emerges lighter before maturing to the darker green shade, and the leaves have a slightly waxy coating that helps them retain moisture.
FLOWER DETAILS
The flowers appear in rounded umbels with multiple star-shaped blooms clustered together on a single peduncle. Each flower has creamy white to pale yellow petals with a contrasting burgundy or deep red corona in the center, creating a striking two-tone appearance. The blooms produce a sweet, pleasant fragrance that intensifies during evening hours, making them particularly appealing for indoor spaces. Hoya sungwookii can flower multiple times throughout the year once mature, typically when the plant experiences consistent care and appropriate light levels. To encourage flowering, provide bright indirect light, allow the plant to become slightly rootbound, and maintain regular feeding during the growing season without disturbing old flower spurs, as Hoyas often rebloom from the same spots.
CARE INSTRUCTIONS
🌞 Light: Bright indirect light is ideal, with 6-8 hours daily. Can tolerate some morning sun but avoid harsh afternoon rays that can scorch leaves.
💧 Water: Allow soil to dry out almost completely between waterings. Water deeply but infrequently in spring and summer, reduce significantly in fall and winter. Bottom watering works well to prevent crown rot.
🌡️ Humidity: Prefers 60-80% humidity range, though it can adapt to average home humidity with proper care.
🪴 Soil: Well-draining, chunky mix with orchid bark, perlite, and coco coir or peat. Soil should dry quickly to prevent root rot.
🏺 Potting: Use small to medium pots with drainage holes, terracotta or plastic both work. Prefers being slightly rootbound. Repot only every 2-3 years or when severely rootbound.
🌱 Growth rate: Moderate growth, producing several inches of new growth over 6 months under good conditions. Can reach 3-6 feet in length within 1-2 years, with mature plants growing even longer if allowed to climb.
👩‍🌾 Fertilizing: Feed monthly during spring and summer with balanced liquid fertilizer diluted to half strength. Skip fertilizing in fall and winter when growth slows.
🐾 Pet friendly: Generally considered safe and non-toxic to cats and dogs, though ingestion may still cause mild stomach upset due to the thick sap.
WHERE TO PUT IT
This Hoya does well in bright bathrooms where humidity is naturally higher, or in living rooms and bedrooms near east or west-facing windows with sheer curtains. It can be displayed on shelves with trailing vines, grown on a small trellis, or mounted on a wall support to show off its climbing nature. Avoid placing it in dark corners, directly in front of heating vents, or in cold drafty areas near exterior doors and windows during winter months.