Hoya Carnosa (Wax Plant, Porcelain Flower) Care & Varieties

Last Updated on March 19, 2022 by Admin

The Hoya Carnosa is the most popular hoya species. Additionally, it has any varieties as well which I’ll go through below.

In any case, the Hoya Carnosa goes by many other names. These include:

Wax plant
Wax flower
Porcelain flower

All the common names stem from the appearance of the flower and leaves which have a waxy surface. These features make it beautiful to look at.

But more than anything, it is the combination of gorgeous leaves and flowers that make the plant well-known.

The Hoya Carnosa has a training habit thanks to its long vining stems. These will allow the plant to climb up large trees in the tropical forests of India, South China and other parts of Southeast Asia, to which it is native to.

For this reason, many growers keep the plant in a hanging basket.

Although, if you want to mimic its natural habitat, you can likewise give it a support to climb on. Trellises and shaped wiring are among the most popular kinds here. Although you can use what you want.

The plant itself features, thick, fleshy succulent-like green oval shaped leaves.

Note that it is not a succulent despite this feature. Therefore, don’t care for it like one. Doing so can lead to too much sunlight and soil that drains too quickly.

Of course, its flowers are just as attractive or more attractive than its leaves. These grow in clusters that look like colorful spherical balls.

Table of Contents

Hoya Carnosa Varieties & Cultivars

The Hoya Carnosa’s beauty exceeds the plant individually as you’ll see a lot of different varieties and cultivars of it around. Some of them include:

Of these, there are a number that are variegated. So, if you prefer bicolored or multi-colored foliage, then you can check them out to see which ones you like the most.

Hoya Carnosa Plant Care

Light Requirements

The Hoya Carnosa does best positioned in bright, indirect light. This is something you want to consider doing because the plant grows the fastest in this condition.

Additionally, bright, indirect light gives it the best chance of blooming.

That said, the plant has no problems with medium and low light. So, for the most part you can place it almost anywhere in a well-lit room.

However, with low light, the plant will not flower.

The most important thing to remember is to avoid the extremes. It does not tolerate overly strong light or direct sun for extended periods of time. Although with acclimation it does get used to the latter.

The risk here is that you’ll see it lose its waxy appearance and its leaves will become dull.

On the other hand, dark locations will not only slow its growth but also keep it from blooming.

Temperature

The Hoya Carnosa is a tropical plant. This means that it prefers warm, sunny climate all year round.

Indoors, this makes temperatures between 60 and 85 degrees ideal for the plant. And it will grow its best if you keep it within this range.

The good news is that it is easy to do so since the most homes maintain these levels. As such, you don’t need to adjust anything to accommodate the plant.

However, be careful the lower temperatures.

Because it does not see snow (or weather below 55-60 degrees much, even during winters in Southeast Asia), it does not have much tolerance for the cold.

Avoid climates below 50 degrees or else you will see its growth slow down. The longer it stays there and lower the temperature gets, the more it will struggle.

This also means that in the outdoors, it is best suited for USDA Hardiness Zones 10 through 12. These areas belong in the southern coastal areas of the country where winters are balm and have sunshine day in and day out.

If you live anywhere with snow or freezing conditions, make sure to take the plant back inside once temperatures drop under 55 degrees.

Humidity

The Hoya Carnosa is a fan of humidity. And it is happiest when humidity stays between 50% and 70%.

That said, its thick, succulent-like leaves allow it tolerate lower humidity.

So, the plant does not mind 40% humidity and slightly lower than that. However, the lower you go, the higher the risk of brown tips and leaves as well as dry, crispy edges.

Once you see that, it is a sign that the plant needs more moisture in the air.

The simplest ways to give it what it needs is to use a humidifier or mist it regularly.

Humidifiers are easy to use but can vary in cost. They also require maintenance. On the other hand, misting is free. But you need to keep repeating it as its effects are only very temporary.

When you do, make sure not to mist the flowers. Similarly, don’t over spritz the leaves such that they get too wet. This can attract fungal and bacterial infections.

Other alternatives include, using a pebble tray and grouping it with other plants.

How Often to Water Hoya Carnosa

During the spring and summer, you’ll need to water the Hoya Carnosa about once every 7 days depending on how sunny it is and how warm the weather gets.

Back off during the winters and allow the soil to dry out a bit. This helps prevent overwatering as it takes much longer for soil to dry due to the colder environment.

In most cases, you’ll be watering the plant once every 2 or 3 weeks during the winter.

That said, the key to watering the Hoya Carnosa is to allow the top 2 inches of soil to dry out before adding more moisture.

The plant is an epiphyte so it does not need a lot of water. Also, its succulent-like leaves store moisture which lets it tolerate dry periods.

source: wikimedia commons

Hoya Carnosa Potting Soil

The ideal soil for Hoya Carnosa is well-draining light and airy potting mix with soil pH of 6.0 to 7.5.

Good aeration, is very important because as an epiphyte, its roots are used more for clinging onto large trees than they are buried in the forest soil.

Therefore, the roots like a lot of air circulation. This is made possible with lightweight, air potting mix.

Similarly, when they do get wet from the rain, the roots dry quickly because there’s a lot of circulated air.

Thus, good drainage is important when it comes to choosing the perfect soil for your Hoya Carnosa.

Fortunately, it is easy to achieve this kind soil. And you can do so in many ways. Here are a few ways.

50% potting soil with 50% orchid bark
50% potting soil with 50% perlite
50% succulent & cactus mix with 50% potting soil
33% orchid mix with 33% cactus mix and 33% perlite

All of these soil recipe mixes will work. The key is that they offer good drainage so the roots don’t end up standing in water.

Does the Hoya Carnosa Climb?

In the wild, the Hoya Carnosa lives on large, tall tree trunks which it climbs in order to get about some of the plants in the battle for more sunlight.

As mentioned, the more bright light it is able to receive, the faster and bigger it will grow. Also, it increases the chances of flowering.

At home, you can mimic these conditions by giving it a trellis of a shaped wire to climb. The plant likes to wrap itself around these supports which makes a decorative structure like a circle or other interesting shapes a good choice.

This way, you can make the Hoya Carnosa grow in the shape of the structure.

Of course, there are many other ways to grow the plant. Hanging baskets are very popular due to the length of the vines. You can also leave it in a pot without any climbing apparatus.

Fertilizer

It is important to feed the Hoya Carnosa to allow it to grow its best. This will let it grow faster and longer as well. You can likewise use any kind of plant food provided that it is not low quality.

The plant is not picky about what kind of fertilizer. Instead, the important this is that it gets its nutrients.

Note that the Hoya Carnosa is a light feeder. So, avoid adding to the dosage listed on the label and don’t feed it more often than needed. Otherwise, the fertilizer could end up burning its roots.

You can use a regular houseplant fertilizer. I like to use a liquid formula because it is easy to dilute. Once a month feeding during spring and summer at 50% strength is all it needs.

And don’t feed during the winter.

To encourage blooms to stay as long as they can, switch to a high phosphorus fertilizer when the plant is about to flower. Keep using it while it is blooming as well.

You can use an orchid bloom booster to do this.

Flowers / Blooms

Speaking of blooms, the Hoya Carnosa is known for its beautiful star-shaped flowers that grow in bunches. These feature a white background with a pink-red center.

While they are small individually, the make their presence felt both visually and by fragrance.

The flowers are amazing to look at because they form spherical balls containing between 20 to 40 blooms each. Their waxy surface also makes them very unique.

Then there’s the aroma, which is fainter during the day but strong in the early mornings and evenings.

But, don’t expect all the Hoya Carnosas to just flower.

First, they need to mature before this can happen. This usually take 1.5 to 2 years or so if you get a very young plant. Then, you need to give it the right living environment.

For the best chances of blooming, it needs bright, indirect sun. Lots of light is necessary.

It also helps to keep it underpotted. So, don’t be in a hurry to repot. This is why you’ll see many growers keep their Hoya Carnosa in the same pot for 5 years or even more.

Pruning

There are a couple of things to keep in mind when pruning your Hoya Carnosa.

Never cut off the spurs or peduncles.
Trim the long vines to shape the plant and control its size.

Of the two, the first one is more important while the second one is more for aesthetic purposes.

The reason you don’t want to prune the spurs even after the flowers are done blooming is that Hoya Carnosas will bloom again from old stalks.

Therefore, if you cut these off, it will need to regrow first before you have any chance of flowering again. This means spending months just to wait for the new stalk to grow.

As for the second part, how often and how much your trim the plant will vary depending on whether you grow it in hanging basket, let it climb or in a container.

How to Propagate Hoya Carnosa

You can propagate your Hoya Carnosa using stem cuttings. This is the easiest way to grow more of this beautiful plant at home for free.

All you need to do is clip off a healthy stem with at least 2 or more leaves.

You can propagate the cuttings in water or soil. Although water propagation is more popular because it allows you to see the roots as they grow.

If you want to root the plant in water, use a glass container so you can see the roots. Also change the water once a week to keep it from getting murky.

Make sure the nodes are submerged in water. But remove any leaves that get into the liquid.

It takes about 3 to 4 weeks for the roots to develop in water. And once they reach 1-2 inches you can move them into toil.

That said, you can likewise keep the plant in water a bit longer.

On the other hand if you decide to root it in soil. Use well-draining potting mix (50% peat with 50% perlite). Moisten the soil and plant the cutting.

Keep the soil moist for the first 1-2 months to encourage root development. Also, try to maintain high humidity for faster results.

How to Repot or Transplant Hoya Carnosa

Repotting is a rare task because the plant likes being snug to the pot. This stress of this kind of tight environment actually helps the plant flower.

Therefore, you don’t need to hurry with repotting.

Also try to avoid moving the pot too much if you can help it.

For one, the plant is not a fan of being moved. Secondly, never do so when it is flowering. This can risk the production of the flower buds and even cause them to die.

That’s because the plant only flowers in the right conditions. So, when you move it and anything changes, especially with light, it can mess up the entire process.

When the time comes to repot, which usually happens between 2 to 5 years, just go up one pot size. Don’t increase it any more than that since the plant enjoys being in a smaller container.

This also reduces the risk of overwatering due to the larger volume of soil.

Is It Toxic/Poisonous to Humans, Cats & Dogs

Not the Hoya Carnosa is not toxic to cats, dogs or humans. This makes it pet-safe and also safe t keep around curious young children.

The plant does not contain any toxics or poisonous components. However, as with eating anything that you’re not supposed to, it can result in some side effects.

Problems & Troubleshooting

Pests

Sap suckers are your Hoya Carnosa’s biggests nemesis when it comes to pests. These include spider mites, aphids and mealybugs.

And from the list, mealybugs are the most likely to come around to attack the plant.

You can treat them all the same way. And the earlier you spot them, the easier and faster it is to get rid of them.

Spraying with water to wash them away is the simplest method. But you need to be through as leaving any adult or egg will allow the entire cycle to start over.

You can likewise use neem oil or insecticidal soap spray.

Diseases

With diseases, root rot is the most serious. But, bacterial and fungal infections can likewise happen if you overwater the plant.

Blight, leaf spot and mold are all harmful but can be limited by controlling water. You can likewise use bactericide or fungicide to get rid of them. Although in the most part limited moisture usually works.