Hoya Callistophylla – Features, How to Grow and Care

Also known as the stiff-leafed Hoya, Hoya Callistophylla is an evergreen climber succulent that looks gorgeous sitting in a pot and is surprisingly easy to maintain. Along with its beautiful leaves, the plant grows tiny flowers that grab your attention immediately. Plus, it is extremely easy to display and equally hard to kill.

If you are looking to buy or grow this plant indoors, keep on reading to know exactly how to do it. You don’t want to kill one of these beauties, do you?

Classification

  • Family: Apocynaceae
  • Subfamily: Asclepiadoideae
  • Genus: Hoya

About the Genus Hoya

Named after Thomas Hoy, a successful botanist and a dear friend of Robert Brown, this genus consists of about 200 to 300 different plant species. All of these plants are tropical and also called wax plants or waxflowers. Their so-called alternative names refer to their leaves’ texture and the fact that they grow tough but beautiful Hoya Callistophylla flowers. These flowers resemble a star with five corners, and each species has different flowers in terms of color, size, and number. Some of the most popular plants of this genus are Hoya Kentiana, Hoya Carnosa, and Hoya Australis.

Common Names and Synonyms

  • Stiff-leaved Hoya
  • Wax plant Callistophylla

Origin and Distribution

Hoya plants are native to Asian countries, including Thailand, Vietnam, India, China, Indonesia, and several others. Many species are also saturated in the Philippines and Australia. However, Hoya Callistophylla originated from Sabah, Malaysia.

Hoya Callistophylla Features

Foliage and Stem

These plants grow beautiful bright green leaves with dark green venation on their surfaces. These leaves grow outwards and can grow up to several inches in size. The petals are generally as long as 1 to 3 centimeters, and the leaves on them are thick, growing up to a size of 25 x 9 centimeters. The stems have a branching growth habit.

Evergreen

These plants are indeed evergreen and are not affected by the passing seasons. This feature is favorable for those who wish to buy or grow the plant for displaying purposes.

Height

A Callistophylla plant can grow up to 3 to 5 meters in length under the right care and environment. These are vining plants to either let them grow upwards on support or grow down hanging from a basket.

Temperature Tolerance

The lowest temperatures that this plant can tolerate are around 50 degrees Fahrenheit. Any lower than this and your Hoya Callistophylla will start falling ill and looking unwell. Hence, take special care of it during the frosty winter season.

Humidity Tolerance

Being succulents, Callistophylla plants are not dependent on humidity. However, they are relatively tolerant of it. These wax plants can do well with moderate to high humidity levels.

Hoya Callistophylla Flowers

Hoya Callistophylla flowers are star-shaped, pale yellow/orange with red tips, and grow in clusters. They bloom in the warmer spring and summer seasons and are a significant attraction feature of the plant. These flowers have a diameter of about 8 to 10 millimeters. As a cluster, their diameter is 4 to 5 centimeters, and each castor has about 30 to 40 flowers in it.

Hoya Callistophylla Fragrance

Just like the Hoya Callistophylla flowers,  the  Hoya Callistophylla fragrance is also one of a kind. It’s beautiful, strong, and unique.

Drought-resistance

Thanks to their succulent qualities, a Hoya Callistophylla is reasonably drought-resistant. It means that they can survive well under dry, water-deficient conditions and will not die immediately.

Pressure Tolerance

Since Hoya plants are called wax plants, it is reasonable to expect a Callistophylla to be resistant to pressure. Thankfully, it is. The tough, waxy leaves secure the plant from damage under acute stress. However, consistent external pressure can slow down their growth and even stunt it. This reason is why you’re advised to keep the plant in a free, open, spacious spot in the house.

Disease and Pest Resistance

Another benefit of having succulent foliage is that these plants are safe from many diseases and pest conditions. However, there are still a few circumstances for which you should be aware, alert, and prepared. These include Botrytis Blight and Scooty mold fungal infections. Pests that are likely to attack your Hoya include mealybugs and aphids.

The primary cause behind each of these problems is inappropriate growing conditions. It could be waterlogged soil, excess humidity around the plant, excessive sunlight, etc. Solving the central problem and fixing what’s wrong can help you eliminate these health issues and bring the plant back before irreversible damage.

Growth

The growth rate of these plants depends on their care and the surrounding environment. However, under optimum conditions, Hoya Callistophylla plants are pretty fast growing.

Toxicity

Unfortunately, all Hoya plants are inedible. Even if they’re not necessarily toxic, animals and children cannot digest their leaves’ structure because it’s so tough and waxy. This indigestion can cause mild to severe symptoms. Hence, you must keep these plants away from any pets or kids you have in the house. Pay special attention if your plant is hanging in a basket, making trails on the floor.

Durability

Their perennial lifestyle makes them very durable, so the Hoya plant can live for a minimum of two to three years and, after that, as long as you give it proper care and environment.

Maintenance

Since they are succulents, Hoya plants do not require a lot of maintenance or effort. They do just fine under room temperature, moderate humidity, and regular watering. Thus, they are relatively low-maintenance.

Dormancy

During the winter season, avoid propagating or pruning these plants as they are dormant. They stop growing and conserve all the food and water you give them. During this time, the best thing would be to feed and water it adequately and let it be. Continue usual care when it “wakes up” in the spring season.

Hoya Callistophylla Care

Hoya Callistophylla care doesn’t involve a lot of extra time, money, or effort.  In fact, it is as simple as watering twice a week, fertilizing monthly, and keeping it nice and warm. Make sure the humidity levels are moderate around it and use the soak-and-dry method to keep it hydrated.

Water Requirements

As mentioned above, use the soak-and-dry method to water these plants. The technique involves watering the plant thoroughly once and letting it dry out for the next couple of days. Until you start to see and feel the top layer drying, do not water the plant again; doing so could waterlog it, and that’s never good. During the dormant months, you should lower the frequency of watering even more.

Soil Requirements

An approximate pH range of 6.3 to 7.5 is ideal for making sure the Hoya Callistophylla grows nicely. Another essential feature of the soil is how well it drains. Remember that the ground should not hold any excess water, because if it does, the roots will suffocate and die. Also, make sure that the earth is rich in organic matter and is fertile for the plant’s maximum growth. Peat Moss is an excellent soil amendment, especially when merged with perlite.

Sunlight

Thanks to the plant’s succulent nature, its leaves are pretty torrent to direct sunlight for most of the year. However, it would be best to protect it from direct exposure during the scorching days of summer. Succulents growing indoors are not used to this kind of harsh environment and may not be able to tolerate it. During such days, either change the plant’s position, put it behind sheer curtains, or use a 20 to 40% shade cloth to mellow the sunlight.

Temperature Requirements

The optimum temperature range for these plants would be 65 to 80 degrees Fahrenheit. However, as mentioned earlier, the lowest temperature before which the plants would start looking ill would be 50 degrees Fahrenheit. Hence, during the icy days of winters, move the Hoya plant to a warmer, more suitable place in the house. It is absolutely essential to do this because if you don’t, these plants’ blooming time will only move further away.

Humidity

Any efforts to maintain the humidity levels around the plant will be highly appreciated. You can install an indoor humidifier to monitor and manage these levels technologically, or you could do it manually by occasionally misting the plants. Approximately 50 to 70% of humidity would be optimal for its healthy growth.

Fertilizer

Try to find high nitrogen content in fertilizers for Hoya Callistophylla since they are foliage plants. Plant food with a composition of 2:1:2 or 3:1: 2 is ideal for maintaining its good health. During the flowering season, fertilizer with an arrangement of 5:10:3 would be much better. Flowering plants need more phosphorus so this combination will be ideal for the blooming Hoya during this time.

Re-potting

You don’t have to worry about re-potting these plants before at least 2 to 3 years. If you think that the plant is outgrowing its current pot or container, feel free to shift it to a bigger one. Just make utterly sure that the new container is also of appropriate size and not too large for it. Upgrading by a few inches in diameter would be enough.

Grooming and Pruning

If you have hung these plants in baskets, you might need to prune them and maintain their length. Although, it is entirely up to your personal choice if you wish to have a long, trailing Hoya Callistophylla.

Just make sure that the plant is always clean and dry to avoid any pest attacks or infections. When you are pruning the plant, take the opportunity to inspect and examine the Hoya thoroughly and make sure it is entirely healthy. Look for dark patches, lesions, and abnormal growth. The sooner you find an abnormality, the sooner you will fix it and prevent irreversible damage.

Hoya Callistophylla Propagation

You can propagate a Hoya Callistophylla by cutting off pieces from its stem. You just need to ensure that the plant you use is fully mature and healthy. If you have the choice, preferably do this during the spring or summer seasons and avoid it during the winter months.

  • Start by sanitizing and sterilizing all of your equipment before you touch the plant. This step is essential to avoid any infections.
  • Choose non-flowering stem cuttings from the Hoya and cut off pieces from it.
  • Take cuttings such that each one has at least two nodes at its end.
  • Next, fill up a plant pot with appropriate soil mix and cover it with plastic. The plastic serves the purpose of maximizing the levels of humidity around the plant. If not this method, you could use a propagator for this purpose.
  • Plant the cuttings in the desired medium and let them be.
  • At this point, you can also keep the cut ends of the cuttings in growth hormones. Doing this helps the growth process speed up and maximizes the chances of successful propagation.
  • Ensure that the surrounding temperature is approximately 70 degrees Fahrenheit. Heated propagators are an excellent way to maintain temperate environments. If not, you can also use bottom heat mats.
  • Don’t overwater or overfeed the plant, thinking it will grow faster. Be very patient and let the Hoya plant take its time.

Timeline

Day 1-14: During this early phase of growth, make sure the plant is safe from external pressure and damage. Give it proper irrigation and drainage.

Week 3-6: Shoots will start to become visible and develop nicely. Pay close attention to the care and environment of the plant during this stage.

Month 2-3: During this period, the plant will need frequent but careful amounts of water and fertilizer.

Hoya Callistophylla FAQs

Hoya Callistophylla Not Growing

If your Hoya Callistophylla is not growing, be sure to water your Hoya Callistophylla regularly, making sure the soil remains moist but not wet. You can also try using a water-soluble fertilizer to help supplement its diet.

Final Thoughts

Whether you want to display it in a pot or hang it in a basket, a Hoya Callistophylla looks beautiful either way. Plus, it doesn’t complain in any of these places either. You can care for it easily, and it’ll stay beautiful all year long. For someone who has a hard time managing and keeping plants alive but still wants a pretty species to add to their indoor setting, this plant would be an excellent choice.