Hoyas are famous as Wax Flower or Wax Plant. This is my favorite plant genus since it’s easy to grow, propagate, and rewards you with fragrant, exotic flowers.
This epiphytic plant can easily extract their nutrients and moisture from the air. This way, they can take care of themselves with minimum effort from your side.
Maintain a regular watering schedule for Hoya Cumingiana during growth and let the soil get fairly dry between watering to prevent root rot.
In addition to good soil and water, this plant requires bright but indirect light for excellent growth.
This species is similar to Hoya Bella, and it originates from Indonesia and the Philippines. It has other names like Bush Hoya or Porcelain Flower and belongs to the Apocynaceae plant family.
The leaves on this plant are small and succulent. They grow closely packed because the internodes are very short, this gives the plant an overall bushy appearance.
The bright flowers add a beautiful contrast to its waxy green leaves.
Hugh Cuming collected the first samples of this plant in Philipinnes; therefore, Cumingiana is named after him. This unusual plant likes growing in an upright fashion. Continue reading to know more about this exotic Hoya.
Table of Contents
Basic Plant Care for Hoya Cumingiana
Soil
Hoyas like their soil to dry out; therefore, good air circulation is a must for this species as well. Another requirement is excellent drainage; therefore, choose a well-draining mixture. Excessively wet or soggy soil will lead to a disaster like killing your precious Hoya.
You can easily create a custom mix yourself by mixing the following ingredients in equal parts:
- Cactus Mix
- Perlite
- Orchid Mix
You can also grow it in a loamy mixture that contains charcoal, bark, leaf mold, and sand in equal parts. Hoya Cumingiana prefers alkaline soil, so keep the soil pH close to 7.5-9. You can add crushed eggshells or oyster shells to lower the pH of the potting mixture.
For outdoor planting, USDA hardiness zones 10, 11, and 12 are considered the most suitable for this plant.
Water
Each plant’s watering needs vary depending on temperature and other environmental factors. However, you can use the soil’s moisture level as a guide to decide if your plant actually needs water. Hoya Cumingiana should be watered when the soil mix feels completely dry; at least 80% of the soil is dry.
While watering, let the water run through the soil entirely. However, do not forget to dump the extra water. Leaving this water increases the chances of fungus and diseases, especially root rot.
If your Hoya suddenly starts dropping leaves, you might be giving your plant more water than it needs. If this happens, do not panic and let the plant dry out a bit.
I always alter my plant’s watering schedule based on its behavior because no fixed watering schedule is suitable for the whole year.
The leaves of this Hoya are also succulent in nature, and it likes being on the drier side. So you do not have to worry much watering this plant.
As a general rule, in summer water when the soil is completely dry, whereas in winter water only to slightly moisten the soil.
This plant has simple watering requirements as long as it’s not overwatered.
Light
I keep my Hoya Cumingiana in an east-facing spot. You can choose any location that receives bright, indirect light. This plant does not mind being in the sun, and 50-70% sun is great for its growth.
Outdoors it should be grown in bright shade or filtered sunlight. Use shade cloths or nets to diffuse the intensity of sun rays.
Direct sunlight is discouraged for this plant, but little early morning or late evening sun will help the Cumingiana bloom better. Mostly higher light encourages more blooms on Hoya plants.
Temperature
This plant is not frost or winter hardy; the foliage will wither and die if exposed to frosty temperatures. The minimum temperature for this plant is 50 degrees Fahrenheit.
On average, they like temperatures ranging from 60 – 85 degrees Fahrenheit.
To avoid temperature fluctuations, do not place it directly near or in front of heaters or airconditioners. You should also avoid draughty doors or windows.
Humidity
Hoya Cumingiana requires moderate to high humidity. However, it can tolerate low humidity. I keep mine in about 70 to 90% indoor humidity level. You don’t have to bother much about humidity for this plant since it’s not picky in terms of this.
But if you want to shower your plant with some extra care, raise the humidity levels in any of the following ways:
- Fill a spray bottle with filtered water. Use this to mist the plant once in a while.
- Place few pebbles in a small saucer/tray. Add water for a few inches; the water should not touch the bottom of the soil. Else the roots will rot. As this water evaporates, the air moisture level rises.
- Group your plants together.
- Buy a humidifier to easily monitor and control the indoor humidity levels. This is great if you want to raise the humidity for several houseplants.
Fertilizer
Before your Hoya Cumingiana starts blooming, feed it with a liquid fertilizer every 2 to 4 weeks. You can also use organic orchid food for this species as organic products are gentle on the plants.
I would recommend using a fertilizer that’s rich in phosphorus as this will help your plant have more blooms.
You can feed this plant monthly during active growing seasons.
Repotting
This plant should be repotted every 1-2 years but at least refresh the soil annually. Prepare a well-draining coarse mixture before repotting. You can refer to the soil section for more details on soil type needed.
Repotting allows more space for root growth on the Cumingiana plant.
Pruning
This aggressive Hoya can get really big and out of control once it enters the mature stage. Prune this plant lightly in the spring season once you feel it’s growing heavily.
Pruning is necessary for this plant to maintain a bushy but neat appearance. You should also trim the foliage if your plant has diseases or fungal infections to get rid of the damaged parts from the plant.
Avoid removing the peduncles while pruning because that’s where the flowers will appear in the next blooming season.
Propagation
Three rooting mediums are discussed below with detailed steps.
Soil Propagation
- Take stem cuttings from a Hoya Cumingiana with at least two nodes. The first step is to find a node; the node is the point where the leaves will emerge on the cutting. Try to pick a vine that has immature leaves and make an inclined cut below the node.
- You can take more than one cutting for propagation. Make sure you use sterilized cutters or shears. Make the cut without damaging any healthy leaves on the plant.
- Dip the end of cutting in the rooting hormone, although this is optional. Rooting hormones have anti-fungal properties and help the cut callus quickly.
- If you want to root the cutting in soil, place it in moist sphagnum moss. Check the cutting every few weeks for any growth.
- Once the root system seems well-established, transfer the cutting to a potting mixture discussed in the soil section.
Water Propagation
- Follow the above steps to take cuttings, but instead of soil, place the cutting in water.
- Water propagation is easy and straightforward, but you need to change the water regularly after every 2-3 days. Stagnant water increases bacterial activity that leads to root rot and lack of oxygen.
- Never submerge the leaves in water; only the node should be underwater. If your cutting has any leaves on the lower parts, remove them.
- Place the water container in a well-lit warm area. For additional warmth, consider adding bottom heat mats. Roots will start emerging in a maximum of 1 month.
- Once established, transfer the cutting to an adequate potting mixture. You can follow the recipes discussed in this article’s soil section.
Perlite Propagation
- This method takes a lot of space compared to others, but it is highly successful for Hoya propagation. Perlite is a sterile material that allows plenty of airflow. This reduces root rot.
- Take a plastic container or tray and fill it with perlite up to 1 inch. Add water and let the perlite soak for a few minutes. Drain the excess water so that the perlite is just slightly damp.
- Bury the stems in perlite but avoid burying the leaves.
- Make a few holes in a plastic bag and use it to cover the container. This will help trap humidity.
- Place the container in a bright area away from direct sun. The temperature should also be warm.
- Once the roots establish, transfer it to a good potting mixture.
Blooms
This Hoya produces the flowers at the end of branches; therefore, the more branches you have, the more your plant will bloom. Like other species, this one also blooms from spurs.
Throughout summer, this Hoya will bloom with fragrant flowers that are star-shaped. The blooms are pale yellow in color with maroon and purple coronas. As the flowers age, they get golden yellow. The flowers are smooth without any tiny hairs that can be seen in other Hoyas.
You will notice that the flowers are more fragrant at night. The pleasant fragrance will remind you of tropical fruits.
Some say the fragrance resembles a scented spice cake. The flowers are present in clusters or umbels, having 5-20 flowers each.
The plant takes about 3-4 weeks from the time the peduncles appear to bloom.
Growth
This plant has a unique growth structure. In the beginning, it will grow upright, and later it starts growing over. This might seems like a small plant, but once it starts growing, it gets quite big.
The growth structure makes this Hoya between an erect, bushy one and a hanging plant. The fleshy leaves are somewhere between oval to rounded in shape.
The foliage for this evergreen plant remains bright green throughout the year. The leaves grow close to each other on long stems and are about 1 inch in size.
If you want to grow your plant upwards, you have a train using a trellis or some other vertical support.
This plant will reach a maximum height of 7 ft and a width of 3 ft, but you have to be very patient for that because it will take somewhere between 5-10 years.
Common Problems for Hoya Cumingiana
Pests
Hoya plants are very resistant to pests, but they can sometimes fall prey to aphids and mealybugs. You will mostly find the pests on this plant near its flowers.
If you find a white waxy substance on leaf joints or other hidden areas, your plant is most probably infected with mealybugs.
Mealybugs often come with newly bought plants from nurseries or online stores. They feed on the plant juices leading to a decline in plant health. They like hiding in joints where the leaf petioles are attached to the stems.
You can get rid of them using horticulture oils, alcohol swabs, or synthetic sprays. Simply spray your plant’s foliage with any of these and repeat the process every week if necessary. Aphids can be treated in a similar manner.
The best way to prevent them from spreading is to quarantine your houseplants for the first 2 weeks. This isolation will help you identify any pests or diseases.
Wrinkled Yellow Leaves
Wrinkled or very thin leaves are an indication of stress for Hoya plants. This might be due to a lack of water content.
If the plant has wrinkled leaves combined with moist soil, then most probably, the roots are rotting. Remove the plant gently from the container and check the root system.
Ensure that your plant is not sitting in wet or compacted soil. Remove any blockage from the drainage areas.
Yellow leaves on Hoya Cumingiana indicates excessive watering. You can solve this by allowing the soil to get dry before watering again. If the soil remains moist for too long, consider transferring the plant to a quick-drying mixture.
Leaf Drop
Your Cumingiana plant is under water stress if it’s growing well but dropping the new leaves before they are even mature. Watch out your plant’s watering schedule to find out whether it’s under or overwatered.
If you were letting the plant dry for too long, water it more. Whereas if you recently watered the plant, let it dry a bit.
Remember that the Hoya Cumingiana needs more water when its blooming or actively growing compared to when its dormant.
Damaged Foliage
Often times Hoyas with succulent leaves develop damaged leaves. This is because of stress during the leaf production process. There could be several reasons; maybe the plant suffered from transplant shock, or it was overwatered, or the temperature was inadequate. Examine all these to find out what is stressing your plant.
Once you provide the right conditions, the plant will start producing healthy leaves again.
Slow Growth
Hoyas are generally temperamental plants. Any change in the environment can lead to partial dormancy or no growth for several weeks or months.
You cannot do much about this just avoid temperature fluctuations and let the plant adjust to its new environment.
This situation mostly occurs when you bring home a new plant. This plant suffers from transplant shock that causes slow growth or no growth at all.
Tips for Growing Hoya Cumingiana
- Every season the plant produces new flowers from old spurs, so do not remove or damage them while handling the plant.
- Protect the Hoya Cumingiana from hot midday sun because that will burn or yellow the leaves.
Frequently Asked Questions about Hoya Cumingiana
How many hours of sun does this plant need throughout the day?
Hoya Cumingiana needs at least 6 hours of bright sunlight. But ensure that the sun does not hit the foliage directly. You can diffuse the sunlight with blinds or sheer curtains.
What happens if the potting soil for Hoya Cumingiana stays waterlogged?
Waterlogged soil is really dangerous for this plant. It leads to yellow leaves, root rot, and eventually, the death of your Hoya Cumingiana. Therefore it’s important to not let the soil stand in water for too long.
Why do the vines on my Hoya Cumingiana keep dying back?
Fix the lighting for your Hoya; make sure all parts of the plant receive bright but indirect sunlight for about 6 hours in the day.
What soil is best for Hoya Cumingiana?
Any soil that has good moisture retention, as well as drainage, works great for the Cumingiana plant. The most common issue for Hoya plants is poor quality soil that either retains no moisture or retains too much moisture.
Conclusion
This is a vigorous trailing shrub that blooms throughout the summer season. The inflorescence for this plant is made up of multiple flowers that hang and are grouped in an umbel. This Hoya is best grown in conservatories, greenhouses, containers, or even along wall sides.
Hoya Cumingiana is one of the easiest houseplants to grow; it’s highly recommended for beginners.