(image credit: IG Alivia Houseplants)
If you are on the hunt for a beautiful thick-leaved plant with clusters of tiny flowers, Hoya Callistophylla is for you.
This beautiful species is an evergreen succulent climber that produces fragrant blooms. The Hoya Callistophylla is a popular indoor plant choice due to its admirable looks and disease-resistant nature.
The Hoya Callistophylla thrives in bright, indirect sunlight and temperatures between 65 to 80 degrees Fahrenheit (18 to 27 degrees Celsius). Owing to its succulent nature, it does well in humidity in the range of 50-70%. The Callistophylla plant enjoys being watered twice a week and grows best in well-draining soils that resist clogging.
According to Flora and Fauna Web, the evergreen Hoya Callistophylla plant is native to the Asian lands, Malaysia, and Thailand, in particular Borneo.
This plant is also known as Stiff-leaved Hoya and Wax-plant Callistophylla. The alternative names refer to the Callistophylla plant’s leaves’ texture and its beautiful flowers.
The Hoya Callistophylla plant is an eye-catcher when hung from baskets or pots. Besides, this beauty has a pretty easy care-guide.
Table of Contents
Hoya Callistophylla Plant Care
Soil
The Hoya Callistophylla plant thrives in well-draining soils that have good aeration. The key is not to let any water accumulate in the roots, as the plant may suffocate and die.
The soil should only hold enough water for the plant to remain hydrated at all times.
The ideal range for this evergreen species is approximately 6.3 to 7.5 (slightly acidic to neutral).
A well-balanced pH is essential for the plant, as it helps it grow and absorb nutrients efficiently. The other vital features are that the soil must be fertile and contain organic matter to ensure good growth.
I suggest using peat moss merged with perlite to make an excellent soil medium for your Hoya Callistophylla plant.
This will provide an aerated soil-mix for the Callistphylla plant that will prevent water-logging and promote growth.
If you plan to grow your Hoya Callistophylla plant in a pot, please ensure that the container has plenty of holes at the bottom that allow all excess water to drain quickly.
Water
The Hoya Callistophylla plant has succulent characteristics. Therefore, watering it every single day is not required.
However, watering it too little can also lead to the plant drying out, and eventually, death. To grow a healthy plant, you must establish a good balance between the two extremes.
A reliable method is the soak-and-dry method. This method is reasonably easy to follow and understand. This technique involves watering the Hoya Callistophylla plant thoroughly, then letting it dry out slightly for a few days.
When you see the top 1 to 2 inches slightly dry, only then water your plant. Overwatering the plant can lead to increased susceptibility and various infections.
On the other hand, an excessively dry plant can lose its natural structure and grow yellow leaves.
Therefore, you should water your Hoya Callistophylla only when its top layer is dry.
Please remember to further decrease the watering frequency during the dormant seasons, winter, and fall. I also recommend you use lukewarm and low-chlorine content water.
Light
Like its fellow species, the Hoya Callistophylla plant thrives in bright, dappled sunlight.
Since it is from the succulent plant’s category, it is considerably resistant to sunlight. However, exposure to direct sun rays for extended periods can lead to significant damage.
Generally, indoor-grown succulent plants do not do well in harsh environments. Therefore, during the peak summer times, make sure your Hoya Callistophylla plant is placed in filtered sunlight.
The sunlight frequency and intensity may change with different seasons. Therefore, if your Callistophylla’s current spot has excessive sunlight falling on it, it is best to change the location.
I recommend you place your plant next to a south-west facing window or put it behind sheer curtains.
You can also use a 20% to 40% shade cloth for mellowing the sunlight. Alternatively, you can make use of artificial growing lights.
Please ensure that the plant gets its fair share of bright, filtered sunlight. If placed in sunlight that is too direct or insufficient, the plant’s growth is adversely affected.
Temperature
The Hoya Callistophylla plant likes moderate temperatures. It is a fairly resistant plant and so does not immediately react to unfavorable temperatures. However, it is best to place it in the optimum range for the plant to reach its maximum potential.
The ideal temperature range for the Hoya Callistophylla plant is 65 to 80 degrees Fahrenheit (18 to 27 degrees Celsius).
The lowest temperature the Wax-plant Callistophylla can withstand is about 50 degrees Fahrenheit (10 degrees Celsius). Beyond this temperature, the plant will wither away.
Maintaining this temperature range is easy for most people living in moderate temperatures.
However, it can be a challenge for those living in colder areas or who experience icy-cold winters. During the winter months, it is best that you bring your Callistophylla plant inside in warmer and more suitable conditions.
Similarly, you can place your Hoya Callistophylla plant in the vicinity of a heater. However, make sure that the plant does not directly come into contact with it.
These plants must be placed in favorable temperature conditions, as failure to do so can result in late blooming and other adversities.
Humidity
The Hoya Callistophylla plant loves moisture. In fact, it loves it so much that it tends to store it in its beautiful green foliage.
The high humidity helps the plant maintain shape and leaf turgidity. However, make sure the humidity level is not too high, as excessive dampness gives way to fungal and bacterial infections.
The optimum humidity range for the Hoya Callistophylla plant is 50% to 70%. Fortunately, most households already fall within this range. Therefore, the Stiff-leaved Hoya plant owners do not have to go through much trouble.
However, if your area’s moisture content is lower than those mentioned above, you might have to make a little more effort.
There are several ways to increase the humidity level of your house. One way is to use a humidifier that keeps the plant’s surroundings sufficiently moisturized and pleasant.
You can also group all your houseplants in one room or simply spray your plant’s surroundings every other day.
Please do not directly spray the plant’s leaves or roots as this may cause root-rot or other bacterial infections.
Fertilizer
The Hoya Callistophylla plant is not a heavy feeder. However, some extra care with high nitrogenous fertilizer will be highly appreciated by this beauty.
I suggest you feed your Hoya Callistophylla with good-quality fertilizer about twice a week or whenever you think it needs some food. You should use high-nitrogen fertilizer that is composed of 2:1:2 or 3:1:2. Similarly, you can feed your plant once a month with a slow-release fertilizer.
You can place the fertilizer a few inches away from the stem to prevent toxicity. However, make sure it is within reach of the plant. The feeding needs of the plant may change according to season. Therefore, feeding the plant during the dormant season is not necessary.
Since the Hoya Callistophylla plant is a flowering species, it naturally needs more phosphorous to produce healthy blooms. Therefore, a fertilizer containing both nitrogen and phosphorous is ideal.
Please do not over-feed your Hoya Callistophylla plant as it will lead to toxicity and plant death. Applying fertilizer to moist soil aids in efficient absorption and also minimizes the probability of toxicity.
Repotting
If you still are not convinced that the Hoya Callistophylla is one of the easiest to manage indoor plants, this fact is most likely to persuade you: the Callistophylla plant is repotted after a good two to three years.
You can forget the hassle of repotting your precious plant every two months or six months.
The Hoya Callistophylla has a moderate growth rate and does not grow too fast. Therefore, frequent repotting is not necessary.
However, if you think your Hoya Callistophylla plant has outgrown its current pot, it is best you shift it to a larger container.
Please ensure that its new pot has adequate drainage and does not allow any water to accumulate in the plant’s roots.
A container that is a few inches greater in diameter is just enough.
Pruning
If you have hung your Hoya Callistophylla plant from a basket or kept it in a pot, you might want to cut its vines short for aesthetic purposes.
However, if you rather let it form large trailing vines, that is also acceptable.
If you wish to prune your Hoya Callistophylla plant, grab a pair of clean pruning shears and chop off any extra or abnormal-looking vines.
Please ensure that you do not cut off too many vines or damage any healthy foliage or flowers.
I suggest you also use this opportunity to inspect the plant closely. Look for lesions, dark patches, or any such abnormal growth.
Get rid of such abnormalities as this will prevent the bacterial or fungal infection, if any, from spreading and causing more damage.
Propagation
The Hoya Callistophylla plant’s propagation is not too challenging. It requires a healthy Callistophylla plant, a pre-prepared soil mix, some water, and sterilized gardening equipment. I recommend you do this during the summer or spring seasons for better results.
Stem Cuttings Method
- Begin with sterilizing and sanitizing all your gardening equipment. This will limit the spread of infection.
- Now choose a non-flowering stem from the Callistophylla plant and cut off a few pieces from it.
- Take such cutting that each one has two or more nodes at the end.
- Next, take your prepared soil mix and fill up a container with it and cover it with plastic. This will maximize the humidity levels in the soil. Alternatively, you can use a propagator.
- Next, plant the cuttings in the soil mix.
- You can add growth hormones or rooting powder to this mix. This will encourage growth and increase the probability of successful propagation.
- Please ensure that the surrounding temperature is favorable (70 degrees Fahrenheit/21 degrees Celsius).
- You can utilize a propagator for maintaining the adequate temperature or use a heat mat.
- Water and feed the plant.
Please be patient while the plant grows. During the first 14 days, the plant needs care in the form of water and good-quality fertilizer. Ensure that your plant is protected from all possible infections during this time.
Between weeks 3 to 6, the plant gives rise to shoots. Please maintain the ideal growing conditions for healthy growth.
After approximately 2 to 3 months, your plant will mature enough to be shifted into a bigger pot. You can now treat it as a healthy mature Hoya Callistophylla plant.
Blooms
The Hoya Callistophylla plant produces exotic star-shaped blooms that are pale yellow or orange with red tips. They are often seen growing in clusters.
The clusters mostly have 30 to 40 flowers each. Together, they form a diameter of about 1.6 to 2 inches (4 to 5 centimeters).
The blooms are one of the most attractive features of the plant. They often sprout in the growing seasons of summer and spring.
The Hoya Callistophylla plant’s flowers are approximately 0.3 inches (8mm) in diameter.
Growth
The Hoya Callistophylla plant is an evergreen species with a moderate to fast growth rate.
However, its growth is primarily dependent on its surroundings and care. In ideal conditions, it is most likely to grow healthy and fairly fast.
The Hoya Callistophylla plant can reach up to 118 to 197 inches (3 to 5 meters) under the right care.
You can either grow the plant upwards by providing it with some support such as totems or let its vines trail downwards from a basket.
The Hoya Callistophylla plant produces bright green leaves that have dark green venation on the surfaces.
The leaves tend to grow outwards, spreading several inches. The petals are mostly 0.4 to 1.2 inches (1 to 3 centimeters) in size, with leaves that are approximately 10 inches in length and 2.3 inches in width.
Common Problems for Hoya Callistophylla
Pests and Bugs
The Hoya Callistophylla is a reasonably resistant plant. However, mealybugs can attack their leaves from time to time.
If infected, start treatment with direct water sprays to bring the bugs down the plant. Next, use insecticidal spray or soap and mist it thoroughly on the Hoya Callistophylla plant’s leaves.
Another common attacker is aphids. They can be present on the Hoya Callistophylla plant’s flowers, particularly the ones producing rich nectar.
For killing the aphids, use insecticidal spray or soap.
Botrytis Blight
The Botrytis Blight, also known as gray mold, is a fungal disease of the Hoya Callistophylla plant. It attacks the buds, flowers, bulbs, and leaves of the plant. It is a major cause of decay in cut flowers.
A plant affected by Botrytis Blight has abnormal-looking flowers with irregular flecks and brownish spots. The same spots also appear on the leaves and stems.
To prevent the possibility of attack, practice good sanitation. Please sterilize all your gardening equipment.
For plants that are affected by Botrytis Blight, use a fungicide, and avoid overcrowding and overfeeding.
Scooty Mold
A common disease of the Hoya plants is Sooty Mold. It often occurs due to the nectar-producing feature of the Hoya plants.
The disease causes the formation of black molds on the plant’s leaves, which sticks to the plant’s saps or nectar.
Aphids can also increase the probability of sooty mold because of their honeydew production.
Luckily, this disease’s solution is pretty simple. To get rid of the mold, simply wipe it off with an antibacterial-sprayed damp cloth.
Similarly, you can mist the plant with antibacterial spray/liquid.
Tips for Growing Hoya Callistophylla
- Use high nitrogen fertilizer.
- Place the plant in filtered bright sunlight.
- Use low-chlorine water.
- Sterilize your gardening equipment before each use.
- Maintain optimal humidity levels throughout the year.
- Use potting soil that is well-aerated and well-draining.
Frequently Asked Questions about Hoya Callistophylla
Why is my Hoya Callistophylla plant not flowering?
This can occur due to a wide variety of reasons. The most common ones include frequent repotting and inadequate sunlight. Please avoid repotting your plant often and place it in bright, dappled sunlight.
Which fertilizer should I use for my Hoya Callistophylla plant?
Please use a fertilizer with high nitrogen for healthy growth and high phosphorous for unrestricted flower growth.
Are Hoya Callistophylla plants evergreen?
The Hoya Callistophylla plants remain green and colorful throughout the year when given the right care, despite the changing seasons.
How long do Hoya Callistophylla plants live for?
The Hoya Callistophylla plants are durable. Therefore, they live for 2 to 3 years or more when given the appropriate care.
Are Hoya Callistophylla plants high maintenance?
Since the Hoya Callistophylla plants are succulent, they do not need a lot of care. They often store up water and survive unfavorable conditions for a considerable amount of time. However, the best results occur only in ideal conditions.
Conclusion
If you are looking for a vivid and lush green plant that does not require too much care, the Hoya Callistophylla plant is an excellent choice.
It can be hung from baskets or allowed to trail down totems. It looks equally beautiful in both conditions.
Most of its types are non-poisonous, and so, it is also pet friendly. If there is any dull-looking corner in your house that needs some brightening up, it is time for you to bring home a Hoya Callistophylla plant.
Some other most popular species of the Hoya plant include Hoya Kentiana, Hoya Carnosa, and Hoya Australis.
Daniel has been a plant enthusiast for over 20 years. He owns hundreds of houseplants and prepares for the chili growing seasons yearly with great anticipation. His favorite plants are plant species in the Araceae family, such as Monstera, Philodendron, and Anthurium. He also loves gardening and is growing hot peppers, tomatoes, and many more vegetables.