The Royal Hawaiian Purple Hoya, a cultivar of Hoya pubicalyx, is a popular plant known for its distinct appearance. This vining plant features long stems with lance-shaped, dark green leaves that often display a subtle purple tint, especially when new, and can have attractive silver flecks. Its appeal also comes from its potential for dark, star-shaped flowers that emerge in clusters, making it a captivating addition to any indoor plant collection.
Cultivating Royal Hawaiian Purple Hoya
Light Requirements
The Royal Hawaiian Purple Hoya thrives in bright, indirect light, which is optimal for its growth and blooming. An east or west-facing window is ideal, providing ample brightness without the harsh intensity of direct midday sun. While it tolerates some direct morning sun, prolonged exposure to strong, unfiltered light can lead to leaf scorching. Insufficient light results in slower growth, reduced foliage color, and less flowering.
Watering Practices
The Royal Hawaiian Purple Hoya prefers its soil to dry out significantly between waterings. Check the top 1-2 inches of soil; water when it feels dry to the touch. Overwatering can lead to root rot, while underwatering causes leaves to shrivel. Adjust watering seasonally: more frequent during spring and summer, and reduced in winter.
Soil and Potting Needs
Royal Hawaiian Purple Hoya benefits from a well-draining and airy soil mix. A suitable potting medium often includes components like orchid bark, perlite, and coco coir, which promote excellent drainage and aeration. This prevents water from sitting stagnant around the roots, mitigating root rot. Choose a pot with drainage holes. Hoyas often flower more readily when slightly root-bound, so frequent repotting is generally not necessary, perhaps every two years or when the plant is clearly root-bound.
Temperature and Humidity
The Royal Hawaiian Purple Hoya thrives with appropriate temperature and humidity. It prefers warm, consistent temperatures, ideally 60°F to 80°F (15°C to 27°C). Avoid sudden temperature fluctuations and cold drafts. High humidity is also appreciated, as this Hoya naturally grows in tropical environments. To increase ambient humidity, use a humidifier, place the pot on a pebble tray, or group plants together.
Fertilizing
During its active growing season (spring and summer), the Royal Hawaiian Purple Hoya benefits from regular fertilization. Apply a balanced liquid fertilizer, or one formulated to encourage blooms, every four to six weeks. Dilute the fertilizer according to package instructions to prevent over-fertilization, which can harm the plant. During the dormant winter months, reduce or completely stop fertilizing.
Propagating Royal Hawaiian Purple Hoya
Propagating Royal Hawaiian Purple Hoya is commonly achieved through stem cuttings. Select a healthy stem with at least two or three nodes, which are the points where leaves and roots emerge. Cut the stem just below a node, ensuring the cutting is about 4-6 inches long, and remove any leaves from the lowest node to expose it.
Cuttings can be rooted in water or a well-draining substrate like sphagnum moss or a mix of perlite and potting soil. When rooting in water, change the water weekly to keep it fresh, ensuring only the node is submerged. For substrate rooting, keep the medium consistently moist but not waterlogged, and place the cuttings in a warm, humid environment with bright, indirect light to encourage root development. Roots typically begin to form within 3-4 weeks.
Troubleshooting Common Problems
Yellowing leaves are a common sign, often indicating either overwatering or underwatering; overwatered leaves may feel soft and mushy, while underwatered ones might be dry and shriveled. Adjusting watering frequency and ensuring proper soil drainage can help resolve this. Nutrient deficiencies can also cause yellowing, often starting from lower leaves, which can be remedied with a balanced fertilizer.
Leaf drop can occur due to extreme temperature changes or prolonged dryness. Pests like mealybugs and spider mites can also lead to leaf damage. Inspecting the plant regularly for these pests and treating them promptly with appropriate horticultural sprays can prevent widespread issues. Lack of new growth or failure to bloom might suggest insufficient light, prompting a move to a brighter location.
Flowering and Mature Growth Characteristics
A mature Royal Hawaiian Purple Hoya produces distinctive and fragrant blooms. The plant forms clusters of star-shaped flowers, typically about 10mm across, ranging from deep purple to almost black, sometimes with pink or red tones, or mixed colors within the same cluster. These waxy flowers emit a sweet, intoxicating fragrance, particularly noticeable in the evening.
Flowering occurs intermittently throughout spring, summer, and fall, with each bloom lasting approximately seven days. Do not remove the spent flower stalk (peduncle), as new blooms will emerge from the same peduncle in subsequent flowering cycles. The Royal Hawaiian Purple Hoya exhibits a vining growth habit, with stems that can reach significant lengths, making it suitable for hanging baskets or training on trellises and other supports.