How to Grow and Care for Hoya Ko Chang Island

The Hoya Ko Chang Island is a specific cultivar of Hoya pubicalyx, named after the island in Thailand where this variety was discovered. This plant has gained attention for its combination of visually striking foliage and wonderfully fragrant flowers. The deep coloration of its leaves provides a dramatic backdrop for its unique blooms, making it a standout in any collection. This hoya is also appreciated for its vigorous growth.

Distinctive Characteristics

The most defining feature of the Hoya Ko Chang Island is its foliage. The leaves are a dark, glossy green, so deep in color they can appear almost black under certain lighting conditions. These leaves are lance-shaped, meaning they are long and narrow, tapering to a point. A silvery or sea-foam green speckling, called a ‘splash’ pattern, adorns the surface.

Its flowers are just as compelling. The blooms grow in clusters known as umbels, with each umbel holding up to 26 individual flowers. Each flower is star-shaped and has a fuzzy texture, with colors ranging from deep burgundy and dark purple to ivory with a pink center. They emit a sweet fragrance, described as chocolate-like or having soft lilac notes. As a vining plant, it grows vigorously and is well-suited for hanging baskets or for training to climb a trellis.

Ideal Growing Conditions

This hoya thrives in bright, indirect light. Placing it near a window where it can receive filtered sunlight is ideal. While it can tolerate lower light, its growth may slow, and it will be less likely to produce its signature flowers. Direct sunlight should be avoided, as it can scorch the leaves.

A suitable soil mix is fundamental for the plant’s health. Hoya Ko Chang Island requires a chunky, airy, and well-draining medium to prevent root rot. An aroid mix, which includes components like orchid bark, perlite, and coco coir, provides the necessary drainage and aeration while retaining some moisture.

Allow the top few inches of the soil to dry out completely before watering again. When you do water, do so thoroughly until water runs out of the drainage holes, but never let the pot sit in standing water. During the winter months, when growth slows, reduce the frequency of watering.

This plant flourishes in warm and humid conditions. Ideal temperatures are between 18°C and 26°C (65°F and 80°F), and it should be protected from cold drafts. Maintaining a humidity level above 60% is beneficial. A balanced liquid fertilizer, applied at half-strength during the spring and summer growing season, will support healthy growth.

Encouraging Blooms

Patience is needed when waiting for Hoya Ko Chang Island to flower, as the plant must first reach maturity. This can take a couple of years, but providing optimal conditions can help. Ample bright, indirect light is one of the most significant factors in encouraging blooms.

Allowing the plant to become slightly root-bound in its pot can also trigger flowering. A hoya that is comfortable and slightly restricted in its container will often shift its energy from vegetative growth to producing buds. Consider switching to a fertilizer with a higher phosphorus content in the months leading up to the blooming season.

Once you notice small buds, called peduncles, forming on the vines, do not move or disturb the plant. Changes in its environment, such as being moved to a new location, can cause stress. This stress can lead to the plant dropping its buds before they open.

Propagation Techniques

Creating new Hoya Ko Chang Island plants is done through stem cuttings. Select a healthy, vigorous vine from the mother plant. It is best to choose a stem that has several leaves and looks robust.

Using clean, sharp scissors, make a cut just below a node. A node is the small bump on the stem where leaves and aerial roots emerge. Your cutting should have at least one or two nodes and a couple of leaves, as this is where new roots will form.

There are several options for rooting the new cutting. You can place it in a glass of water, ensuring the node is submerged, or plant it in a container of moist sphagnum moss or perlite. Keep the cutting in a warm spot with bright, indirect light and maintain consistent moisture until a healthy root system has formed, which can take several weeks to a few months.