Hoya Pubicalyx Care & Propagation (#1 Definitive Guide for THRIVING Plant!)

hoya pubicalyx purple flowers and thick green leaves

Hoya Pubicalyx is a succulent-like flowering plant that is both low-maintenance and easy to grow. It has many varieties that produce clusters of scented purple-black to pinkish-silver flowers, some featuring beautifully speckled leaves.

Care-wise, it requires: bright indirect sunlight and high humidity, 60-70% being ideal. Don’t let the temperature fall below 50 degrees F (10 degrees C). Sufficient sunlight will help blooming, as will a slightly root-bound plant. Use rainwater or filtered water to avoid water marks on leaves.

Origins

Hoya Pubicalyx is native to the Philippines, and it was first collected in Luzon Island in 1913. In nature, this Hoya is found in humid regions and thrives under the canopy of trees under indirect bright sunlight.

How to Care for your Hoya Pubicalyx

Light

In its natural habitat, the Hoya Pubicalyx grows under the canopy of trees. This is why bright indirect sunlight is essential for its growth. East-facing windowsills are an excellent choice, as this gives your plant some exposure to morning sun and indirect light for the rest of the day.

Exposure to morning sun (which is less harsh) is fine and encourages your Hoya’s foliage to grow vibrant.

On the other hand, keeping the plant under direct sunlight during afternoon and midday sun can burn it. You can use a 20-40% shade cloth to filter harsh light.

Water

Hoya Pubicalyx is a relatively drought-resistant plant but still requires watering regularly. The ideal time to water is when the top 2 inches of the soil are dry. Overwatering this plant can lead the roots to remain in standing water and increase the chances of fungal infections and root rot. 

Filtered water and rainwater are best suited for plant health as hard water can be detrimental and leave water marks on the leaves. Make sure to remove the excess water from the saucer when you’re done watering. 

Humidity

Being a tropical plant, one thing that your plant loves is humidity! 60-70% humidity is ideal, but it can also be hard to maintain in some climates. 

Regular misting, using a humidifier, or placing your plant on a pebble tray are some ways you can create humidity for your plant. Again, it is better to use filtered or rainwater as it is good for the plant and prevents water spots from forming on the leaves. 

Temperature

The tropical regions where Hoya Pubicalyx is naturally found are hot and humid. Therefore, the ideal temperature range for this plant is about 60-75 degrees F (16 – 24 degrees C).

Furthermore, you must ensure that the temperature doesn’t drop below 50 degrees F (10 degrees C) in winter. Shift your plant to warmer areas when things get chilly. Your plant is not cold-hardy.

Growth

Hoya Pubicalyx is a fast-growing plant, and its vines can grow up to 20 feet (6 meters) long, given that all its nutritional needs are being met. New plants can take 1-2 years before they start blooming, and after that, they bloom in spring and summer. 

The flowers are star-shaped, small in size, and grow in clusters. As we already discussed, there are a variety of cultivars that produce different color variations. The flowers emit a sweet fragrance at night. 

hoya pubicalyx prior to blooming
Hoya Pubicalyx prior to blooming
Photo credit: cmyip, iNaturalist. All rights reserved.

Soil

There’s three characteristics that are crucial to your Hoya’s soil. It needs to be airy, nutrient-rich and well-draining.

Ideally, mix together organic compost, perlite, and high-quality orchid potting mix in equal parts. The charcoal, pumice and pine bark contained within the orchid mix makes the soil very well-draining, with added perlite to enhance breathability. Compost gives it a boost of nutrition for a healthy plant.

Toxicity

Hoya Pubicalyx is a non-toxic plant that is safe to keep around pets and children.

However, like all Hoyas, this plant secretes a white sap that can be irritating for the skin. For this reason, it’s best to wear gloves when you’re pruning your plant. 

Fertilizer

If you’re not careful, you run the chance of overfertilizing your Hoya Pubicalyx, as they are a light feeder. If you’ve already added compost as part of the potting mix, you definitely shouldn’t add any more fertilizer!

However, if you’ve opted for a potting mix that doesn’t contain added nutrients, you can use a liquid fertilizer that is diluted to half its strength. Use it just once a month during the growing season.

Another way to fertilize your plant is through foliar feeding. It is when you apply the fertilizer directly to the leaves by using spray or mist. Whatever the case, remember that there is no need to fertilize during winter because that is when the growth slows down or stops. 

a hoya pubicalyx being trailed up a stick, with lush green succulent-like leaves

How to Detect Nutrient Deficiency?

There are some signs and symptoms that can alert you of a specific nutrient deficiency in your Hoya Pubicalyx plant:

  • Nitrogen deficiency. If the growth seems stunted or slowed down, or the older/lower leaves turn yellow or fall off, your plant has a nitrogen deficiency. 
  • Phosphorus Deficiency. A phosphorus deficiency in your Hoya Pubicalyx will lead to the rusty colour appearing on the leaves’ edges. New growth will also stop. 
  • Potassium Deficiency. Potassium deficiency will lead to a tan colour appearing on leaves’ edges, and the newer leaves will grow closer together on the stems. 

Repotting

It is not very often that a Hoya Pubicalyx plant needs to be repotted, as they prefer to be slightly root-bound. However, on rare occasions, it might show some signs that it needs a new home. 

One sign is when the growth slows down or stops. When that happens, and you’re certain that all the nutritional needs are being met or that there are no signs of pests or plant diseases, it is about time to repot your plant. Otherwise, seeing roots peek out of drainage holes is another tell-tale sign.

Steps to Repot Hoya Pubicalyx

  1. Remove the plant from its container and gently remove the soil around the roots.
  2. Fill the base of the new container with well-draining and well-aerated soil mix and place the plant inside. 
  3. Fill the rest of the space around the plant with your preferred soil mix. 
  4. Ensure that the new container is only one size larger (about 2 inches, 5cm) than the previous one to avoid filling it with more soil than necessary. Doing so leads to overwatered plants.
  5. Always use containers with a drainage hole.
  6. To ensure the plant is safe from excess moisture, use terracotta pots. They are made up of a porous material that helps evaporate excess moisture. 
topview of Hoya Pubicalyx splash
Potted Hoya Pubicalyx Splash.

Pruning

You can prune your plant to keep its shape, and to cut off any damaged leaves. Do so in the spring or summer, but NOT when you see flower buds starting to form.

If you see flower buds, let your plant continue to focus its energy on growing flowers. If you prune during this time, the flowers may not develop as your plant will need to spend energy recovering instead.

Propagation

It is quite easy to propagate Hoya Pubicalyx. The go-to method and also the easiest for its propagation is by planting a stem cutting in soil. The best time to propagate is during the growing season for better and faster root growth in its new home. 

Here are a few easy steps to take when propagating your Hoya Pubicalyx plant. 

Steps to Propagate Hoya Pubicalyx

  1. Cut a 5-7 inch piece of the stem using sterilized garden shears or scissors.
  2. Cut off the lower leaves on the stem and plant it about 4 inches deep in the soil.
  3. The soil needs to be moist until the stem cutting develops roots. You can help the soil retain moisture by wrapping a plastic bag over the container.
  4. Just like the plant, the cutting also needs bright indirect light throughout the day. 
  5. Place the cutting in a place that is less prone to temperature fluctuations.
  6. Once roots are formed, it is up to you to leave the cutting in for continued growth or transfer it to the final container. 

Common Diseases

Blight

Blight is a fungal infection that can harm various parts of your Hoya Pubicalyx plant. It appears in grey patches on the leaves and the stems. In advanced stages, this fungus can make the plant feel mushy or cause it to droop.

To get rid of blight, remove the affected plant tissue as much as possible with sterilized garden shears. Use a 70% isopropyl solution to sterilize shears to avoid contamination and spread. Quarantine the plant away from others. Then, treat the plant with a copper fungicide to stop further infection. 

Blight can form in the presence of high humidity. Avoid overwatering your plant, and prevent the water from sitting on the leaves for too long after misting can help prevent the recurrence of blight. 

Common Pests

The most common pests that are attracted to Hoya Pubicalyx are sap-sucking insects. Two of the most common perpetrators are mealybugs and root rot nematodes. 

Mealybugs

Mealybugs are a common plant pest that is white and fluffy in appearance. They love to devour the plant sap and cluster around the base of the leaves. As they feed, they secret honeydew which weakens and damages the plants. 

In the early stages, mealybugs are easy to spot and get rid of. But you need to act quickly. With an advanced infestation, the plant starts to wilt, and new growth dies off. 

Read our step-by-step guide on how to identify and get rid of mealybugs.

4 Most Common Hoya Pubicalyx Cultivars or Varieties

Here’s a list of some of the most common Hoya Pubicalyx cultivars or varieties and their unique characteristics.

Black Dragon

Black Dragon is a unique-looking Hoya Pubicalyx variety in the sense that, unlike other varieties, it has lime-green leaves without any speckles. Its flowers are of a beautiful dark purpley-black color with red centers. They are small and shaped like stars. 

These flowers grow in bouquet formation in the springtime and give this variety an exotic look that many gardeners love. This cultivar gets its name because of its imposing flowers. Black Dragon variety has been renamed as Hoya pubicorolla ssp. Anthracina.

Photo credit: the.leafing.room. Used with permission. All rights reserved.

Pink Silver

The Pink Silver variety has green leaves with silvery variegation. It gets its name because, in the presence of adequate sunlight, the leaves of this cultivar change colors into pinkish silver. Its flowers are pale red with pink centers.

Red Buttons

The Red Button cultivar of Hoya Pubicalyx is named for its dark purple flowers with slightly red centres. The most interesting aspect of its appearance, apart from flowers, is its green leaves which can sometimes show patches of red and purple. 

Royal Hawaiian Purple

Royal Hawaiian Purple also blooms tiny star-shaped flowers in clusters. These flowers can have either pinkish-red or black shades. Its leaves are green with silvery-grey smudge patterns. This cultivar can bloom different coloured flowers in a single cluster on rare occasions.

Apart from the cultivars mentioned above, Hoya Pubicalyx has a variety of cultivars such as Jungle Garden, Dapple Gray, or Bright One. 

Troubleshooting your Hoya Pubicalyx

How can I encourage my Hoya to Bloom?

The best way to ensure that your Hoya Pubicalyx blooms to its full potential is sunlight. Ideally, your plant should receive at the very least 6 hours of bright and indirect sunlight every day. If it still does not bloom, move your plant to a spot where it can receive a couple of hours of direct early morning sunlight.

If natural light conditions are not sufficient, use a grow light to boost to your plant’s growth.

Also, do not trim the penducle (flower stalk) once a flower has bloomed and died off. New flowers use the same old penducles to grow! This will save your plant from spending energy on growing a new stalk for the next blooming season.

How can I Remove Water Spots from my Plant’s Foliage?

Water spots may appear on the leaves surface over time. These are mineral salt deposits that appear due to using hard water to water plants.

Here are a few easy steps you can follow to remove water spots from your plant’s foliage:

  1. Dilute a few tablespoons of lemon juice or vinegar with water.
  2. With the help of a soft and clean cloth, wipe the leaves gently with this mixture.
  3. Since deposits are found on the upper parts of the leaves, use this solution to clean that area only.
  4. Do not apply the solution underneath the leaves because that area contains pores and stomata.

If you want water spots from appearing, use filtered water or rainwater to water your plant. 

Hoya Varieties

There are some similar Hoya varieties that people often confuse with Hoya Pubicalyx. Let us see what they are and how to differentiate between the two. 

Hoya Carnosa

Hoya Carnosa, also known as Porcelain flower or wax plant, is a common houseplant. It has similar characteristics to Hoya Pubicalyx, and people sometimes confuse one with the other. 

The best way to differentiate between the two plants is to look at the leaves. The leaves of Hoya Pubicalyx are longer and narrower, while the Carnosa leaves are shorter in length and shaped somewhat like an American football. 

Hoya Pubicalyx Splash (or Speckled)

People may use different names like splash and speckled for Hoya Pubicalyx to describe the silvery variegation on the leaves.

Some Hoya Pubicalyx varieties or cultivars have “splash” or speckled patterns on its leaves.
Photo credit: bronzit, iNaturalist. All rights reserved.

Hoya Curtisii

Hoya Curtisii is one of the unique varieties that is relatively easier to distinguish because of its tiny teardrop leaves and distinct flowers. The flowers grow in clusters too, and the plant is a trailing plant, just like other similar plants to Hoya Pubicalyx. 

hoya curtisii plant

Hoya Linearis

Hoya Linearis is by far the easiest Hoya variety to distinguish. Unlike big waxy leaves, Hoya Linearis has fuzzy, needle-like leaves that hang off in masses and give this plant a curtain-like look. 

Its flowers are also unique in shape and color. They start as small peduncles and bloom into clusters of pleasant white flowers. 

hoya linearis in a white pot sitting on a tree stump

Other great Hoyas to check out

Frequently Asked Questions

Can I use LECA for Hoya Pubicalyx?

Hoya Pubicalyx loves breathable growing media and hates waterlogged roots, which is why LECA has proven to be an excellent substrate for these plants. It is beneficial to use LECA for Hoya Pubicalyx. Here’s the lowdown on LECA for you to decide if its right for you.

How do I train my Hoya to Vine?

Hoya Pubicalyx is a vining plant, and seeing it vine to its full potential is a beautiful sight. Even more remarkable is how easy it is to train this plant to vine. 

All you have to do is loosely wrap a few vines around things and areas you want your plant to trail on. You can use garden ties to loosely secure the vines in place. Gradually, the plant will grab, twist around, and keep growing in that direction until you have a long and healthy-looking Hoya vine. 

Wrapping Up

Care summary:

  • Lots of bright, indirect light and some gentle morning direct light encourages blooming. East-facing windows are optimal.
  • Use rainwater to avoid water marks on your plant’s leaves, water only when top 2 inches of soil are dry to the touch.
  • An airy mix of orchid potting soil, perlite and compost is ideal.
  • Aim for humidity of 60-70% and average room temperatures.
  • Fertilizing is not necessary if you are using compost in your potting mix, otherwise a liquid fertilizer at half-strength once a month during growing season is sufficient. Don’t overfertilize.
  • Repot infrequently; your plant likes being slightly root-bound.
  • Prune for a bushy look, but avoid cutting off flower penducles. Let old flowers fall off naturally.
Deborah

Deborah is a plant enthusiast and founder of Gardening Collective.

Comments are closed.