Sweetheart Hoya

Hoya kerrii is native to Southeast Asia, specifically found in Thailand, Laos, Cambodia, and Vietnam, where it grows as an epiphyte on tree trunks and branches in tropical deciduous and evergreen forests.

• Found at elevations from 200 to 800 meters in tropical forests, where it clings to tree bark using adventitious roots and grows in the dappled shade of the canopy
• First discovered and described by the French botanist Cornélis Andries Backer, and named in honor of Arthur Francis George Kerr (1877-1942), an Irish physician and botanist who collected extensively in Thailand
• Kerr was a prolific plant collector who sent thousands of specimens to herbaria worldwide, and many Southeast Asian plants bear his name, including this beloved hoya
• Introduced to cultivation in the 20th century and rapidly gained popularity as a houseplant due to its unique heart-shaped leaves and easy-care nature
• In its native Thailand, the plant grows in seasonal tropical forests with distinct wet and dry periods, explaining its succulent leaf adaptation for water storage
• The species exists in several forms in cultivation, including the standard dark green form, a reversed variegated form with yellow centers, and a border variegated form with white or yellow margins

Stems: Slender, climbing and trailing, producing aerial roots at nodes, 1-3 m long, somewhat succulent, green to purplish, slightly pubescent, 2-3 mm in diameter.
• Stems are flexible and can be trained around supports
• Aerial roots emerge from nodes and adhere to bark or moss poles

Leaves: Thick, fleshy, succulent, perfectly heart-shaped (cordate), 5-15 cm long and 5-12 cm wide, dark green (variegated forms have white, cream, or yellow margins or centers), glabrous, leathery, with prominent pinnate venation.
• Leaves store water, allowing the plant to tolerate extended dry periods
• Each leaf is a near-perfect heart shape — among the most symmetrical leaf forms in the plant kingdom
• Leaves emerge in opposite pairs along the stem

Flowers: Borne in convex umbels of 15-25 small star-shaped florets, each floret 8-10 mm across with 5 reflexed corolla lobes and a central corona, creamy white to pale yellow with a darker pink to maroon center.
• Flowers produce copious, sticky, clear nectar that often drips from the umbel
• Fragrance is sweet and noticeable, strongest in the evening
• The same umbel reblooms year after year from the persistent peduncle
• Blooming occurs primarily in summer but can happen any time of year

Roots: Fibrous, with clusters of aerial roots at nodes for climbing and moisture absorption.
• Roots are adapted for growing in bark crevices rather than soil

Habitat: An epiphytic vine in the tropical forests of Southeast Asia (USDA zones 11-12). Grows on tree bark in filtered canopy light, absorbing moisture and nutrients from rainwater, humid air, and organic debris that collects around the roots. Never found growing in soil in its native habitat.

Water Storage: The thick, succulent leaves store significant quantities of water, allowing the plant to survive extended dry periods between rain events. This adaptation makes it one of the most drought-tolerant houseplants, thriving on neglect and suffering quickly from overwatering.

Pollination: In its native habitat, flowers are pollinated by small moths, flies, and ants attracted to the copious nectar. The flowers' evening fragrance and nectar production are adaptations for moth pollination (phalaenophily). In cultivation, the nectar is so abundant it often drips from the flower clusters.

Reblooming: One of the most remarkable features of hoyas is that the flower peduncle (stalk) persists after blooming and produces new flowers from the same point year after year. This means old peduncles should never be removed, as they will generate the next season's blooms.

Growth Rate: Slow-growing compared to many houseplants, producing only a few new leaves per year. This slow growth contributes to its popularity as a low-maintenance plant.

Light: Grow in bright indirect light — an east or west-facing window is ideal. The plant tolerates medium light but growth slows significantly. Avoid direct midday sun which scorches and yellows the thick leaves, causing permanent brown patches. Variegated forms need slightly more light to maintain their coloring.

Soil: Use a well-draining succulent or epiphytic mix — combine standard potting soil with generous amounts of perlite, orchid bark, and pumice. The mix should drain almost instantly. As an epiphyte, the plant is adapted to growing in bark crevices, not dense soil. Avoid heavy, water-retentive mixes that cause root rot.

Watering: Water only when the soil is completely dry and the leaves begin to feel slightly soft and flexible — typically every 10-14 days in summer and every 3-4 weeks in winter. Overwatering is the single most common cause of death, causing root rot that spreads rapidly through the succulent stems. When in doubt, underwater.

Temperature: Thrives at 18-27°C. Keep above 10°C at all times — the plant is not frost-tolerant. Avoid cold drafts and sudden temperature changes. Higher temperatures are fine if humidity and light are adequate.

Humidity: Tolerates normal indoor humidity (30-50%) but appreciates higher levels. In very dry environments, the leaves may develop brown, crispy edges. Misting provides only brief benefit.

Propagation: Propagate from stem cuttings with at least 2 leaves and a node. Single-leaf cuttings without a node will root but rarely produce new growth — they can survive as a single leaf for years, which is how they are sold as "sweetheart plants." For a full plant, cuttings must include a stem node where new growth originates. Root in moist perlite or sphagnum moss.

Support: Provide a small trellis, hoop, or moss pole for climbing, or allow to trail from a hanging basket. The trailing habit creates a beautiful cascade of heart-shaped leaves.