Hoya subcalva is a unique plant admired for its large, fragrant flowers. Its exotic nature makes it a popular choice for indoor gardens.
Understanding Hoya Subcalva
Hoya subcalva is a vining plant native to Papua New Guinea. It is suitable for hanging baskets or training on supports. Its vibrant green, glossy leaves typically measure about 15 cm long and 5 cm wide and can develop a subtle veining pattern.
Flowers emerge in clusters of up to 40 star-shaped blossoms. These deep pink flowers often have a lighter apricot streak on the corolla, resembling delicate porcelain. They have a strong, sweet, unique fragrance, often described as reminiscent of grape juice or candy. Flowers last up to a week and bloom frequently, especially from October to April.
Hoya Subcalva Care Guide
Light
Hoya subcalva thrives in bright, indirect light, mimicking its natural habitat where light filters through a tree canopy. Placing the plant near east or south-facing windows can provide ample morning sunlight without the harshness of direct afternoon rays, which can scorch leaves. Insufficient light can hinder growth and prevent blooming, while too much direct sun may cause leaves to yellow or redden.
Watering
Water Hoya subcalva consistently and moderately. Allow the soil to dry between waterings, similar to succulents, to prevent root rot. During the active growing season, typically spring and summer, watering every 7-10 days may be appropriate, allowing the top inch or two of soil to dry before rewatering. In cooler months, watering frequency should be reduced significantly, sometimes to about once a month, ensuring the soil is thoroughly dry.
Soil and Potting
Hoya subcalva requires a well-draining, airy potting mix. Ideal mixes include orchid bark, perlite, coco coir, or sphagnum moss, ensuring good aeration and preventing waterlogging. The plant tends to flower more prolifically when slightly root-bound, so frequent repotting is not necessary; repot only when roots have filled the current pot.
Temperature and Humidity
This tropical plant prefers warm environments, 18-29°C (65-85°F). Protect it from drafts and temperatures below 14°C (57°F). Hoya subcalva also benefits from high humidity levels, ideally above 60%. Methods to increase humidity include misting, using a pebble tray, or placing the plant near other plants.
Fertilizing
During the spring and summer growing season, fertilize regularly. Apply a balanced liquid fertilizer every 2-4 weeks at half strength. Some growers switch to a fertilizer with higher phosphorus content to encourage blooming. Fertilization should be reduced or paused during the plant’s semi-dormant period in fall and winter to prevent nutrient buildup and root burn.
Propagating Hoya Subcalva
Propagate Hoya subcalva using stem cuttings. Take a healthy stem cutting, ideally 4-6 inches long, ensuring it has at least one or two nodes. After making a clean cut, allow the cutting to air dry for several hours to a day to form a callus, which helps prevent rot.
The prepared cutting can be rooted in water, where root development is visible, or in a light, well-draining medium such as perlite, sphagnum moss, or a succulent/cactus mix. When rooting in a medium, ensure at least one node is buried. Maintain warmth and humidity around the cuttings, and once roots are about 1-2 inches long, the new plantlets are ready for transplanting into a suitable potting mix.
Common Problems and Solutions
Yellowing leaves often indicate improper watering (too much or too little). Overwatering results in soft, mushy yellow leaves, while underwatering causes individual leaves to turn dry and yellow. Adjusting watering habits to allow the soil to dry completely between waterings usually resolves this.
Leaf drop can occur due to environmental stress, such as sudden temperature changes or insufficient light. Ensuring stable temperatures and adequate bright, indirect light helps prevent this. A lack of blooms often points to insufficient light or the plant not being mature enough. Moving the plant to a brighter location or providing supplemental grow lights can encourage flowering. Pests like mealybugs and spider mites can affect Hoya subcalva. Inspecting the plant regularly and treating infestations with insecticidal soap or neem oil can manage these issues.