Hoya Imperialis Varieties & Care Guide

Last Updated on March 19, 2022 by Admin

The Hoya Imperialis is also called the Imperial Hoya. This is because of its regal-looking blooms which are stunning even amongst hoyas.

It features larger flowers which give you bigger sized clusters as well (larger than your hand). And the star-shaped flowers are more pointed making them very distinct compared to other hoya species.

The regular Hoya Imperialis has red/maroon flowers with white and pink middles that feature another smaller shaped blossom there.

However, don’t be surprised to see many other colors as well. That’s because the Hoya Imperialis has a number of varieties available. Here are some of the more well-known Hoya Imperialis varieties.

Hoya imperialis Red
Hoya imperialis Palawan
Hoya imperialis Var Rauschii
Hoya imperialis Purple
Hoya imperialis White

In most cases, their names are based on the color of their flowers. But some are named after where they come from or were discovered as well.

In addition to its beautiful flowers, the Hoya Imperialis is also a standout amongst hoyas because of a few other things.

It is larger than many other hoya species. As such, its blooms are bigger. Additionally, it is a fast growing vining plant. in contrast, many hoyas are slow growers.

This allows it to grow longer and denser than the others.

Unfortunately, it can get messy as it gets longer. So, there’s a bit more pruning involved as well.

Its leaves are lovely as well thanks to their smooth, glossy green appearance.

The plant originates from Malaysia and is native to Southeast Asia.

Table of Contents

Hoya Imperialis Plant Care

Light Requirements

The Hoya Imperialis enjoys medium to bright light provided that it stays away from direct sun for extended periods of time.

Thus, the best spot for the plant is a well-lit room. And if you have a location that’s near an east or west facing window, that would be ideal.

In general, the plant thrives with morning sun and afternoon shade. That’s because the morning sun is much gentler than that during mid-day.

As such, it actually appreciates direct morning sun (before 10:30 a.m. which makes an east, northeast and southeast facing windows great spots.

If you leave it in near a west facing window, it is important to know what it can tolerate 1-2 hours of direct afternoon sun but nothing more than that.

This means it is a good idea to distance it from the window away from the rays or filter the light using something like sheer curtains.

If you don’t get a lot of natural light indoors, you can likewise use grow lights. But with artificial lights, you’ll need at least 10-12 hours of exposure daily.

However, with them, your plant does get the benefit of receiving consistent lighting even through winter which is not always the case with natural light.

Temperature

The Hoya Imperialis enjoys temperatures between 60 and 95 degrees Fahrenheit. And it prefers the mid to higher end of this range. As such, it enjoys slighting warm conditions compared to other hoyas.

It is worth noting that with hoyas, they generally like similar climate environments.

However, depending on where they come from and whether they originated in the lowlands or in higher elevations, their temperature preferences can vary a bit.

This is why some species like the Hoya Carnosa and the Hoya Lacunosa prefer slightly cooler weather (between 50 to 75 degrees Fahrenheit).

On the other hand, the Hoya Imperialis and the Hoya Pachyclada like a slightly warmer temperature range.

Humidity

Similarly, the level of humidity different hoyas will tolerate is likewise affected by where they came from. Additionally, it is a good idea to check the thickness of the leaves as well.

Some hoyas have very thick, succulent-like foliage. Some have slightly thinner but will store some moisture as well. And there are others hat don’t have too much of a succulent feature.

As such, the thicker the leaves, the more they’ll be able to tolerate lower humidity. And that would make it do better in regular household humidity.

That said, hoyas in general enjoys humid conditions as most come from Southeast Asia whose weather is mostly hot and humid.

And such is the case for the Hoya Imperialis.

It thrives when humidity is 50% and above.

This means that it can be challenging to care for the plant if you live somewhere with dry air. Similarly, cold winters and hot summers also tend to dry out the air. So, you do want to see how low humidity gets during those times.

If it drops significantly, or your home humidity is consistently low, it is a good idea to invest in a humidifier. You can likewise mist the plant a few times a week or place it on top of small rocks in a water tray.

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How Often to Water Hoya Imperialis

The Hoya Imperialis enjoys regular watering. Although you do want to be careful with overwatering as the plant’s roots are susceptible to it.

As such, there are two things to keep in mind when you water the plant.

Allow the soil to dry before adding more water – wait until the soil is at least 50% dry before watering. It is an epiphyte which means its roots like to go dry between waterings You can likewise wait until the soil dries all the way before adding more moisture. However, avoid leaving it bone dry for prolonged periods of time.
Water thoroughly – on the other hand, it roots also need a good amount of water. To keep them hydrated, drench them when you water. You can do so by flooding the root ball until it begins to drip from the bottom of the pot, then stop. This gives the soil enough moisture to keep them hydrated. It also helps flush out the fertilizer salts that have accumulated in the soil.
After watering, allot the plant to drain completely – right after soaking the root ball, let the plant drain completely before putting it back to its place. If you leave a saucer or something else to catch the water at the bottom of the pot, make sure to throw that excess water away as well.

Hoya Imperialis Potting Soil

The most important thing about Hoya Imperialis soil is that it needs to be well-draining. This will ensure that the plant’s roots stay hydrate but don’t end up standing in water for extended periods of time.

Instead, the excess moisture is drained from the soil which keeps the roots dry soon after you water.

This will prevent any risk of overwatering, waterlogging and root rot.

As such, the most important things with Hoya Imperialis potting soil are:

Fast draining
Good aeriation so the roots can breathe
Does not get compacted
Does not stay wet or soggy for long periods

Fortunately, there are many ways to achieve this.

Here are some DIY potting mix recipes for Hoya Imperialis you can make at home.

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

The important thing is to ensure that there is enough drainage. And you can use perlite, pumice, orchid bark, fir bark, charcoal and similar ingredients to achieve this.

The other thing to keep in mind is to make sure to use a pot with drainage holes. This will allow the moisture that drains from the soil to exit the container instead of collecting at the bottom of the pot.

Fertilizer

The Hoya Imperialis is not too fussy about fertilizer. As long as it gets the nutrients it needs, it does not mind what kind you use.

As such, you can use organic fertilizer along with the potting mix you use. In this case, you can use compost or worm castings.

Likewise, you can go with fish emulsion or slow-release fertilizer. With fish emulsion, make sure to apply in an open space. That way, your room won’t smell fishy right after.

In most cases, it is just easier to use chemical fertilizers since you can just pick them up from store shelves and follow the instructions on the label.

All of these work well.

The important thing is to avoid overfertilizing the plant. Just give it what it needs. That’s it.

This means feeding the plant during spring and summer with a balanced liquid fertilizer. Once a month or once every two weeks works well.

You don’t need to feed it during late fall and in the winter.

Flowers / Blooms

The most attractive part of the Hoya Imperialis is its flowers. Even for hoyas, the Imperialis has a very unique look. And its distinctive blooms set it apart from the others.

That said, its flowers do have some similarities with other hoya species as well.

They grow in clusters. As such, expect a few of them to grow as a group. Although, with the case of the Hoya Imperialis, the size of the flowers are bigger. So, you have fewer blossoms per cluster.

Each of these clusters can have anywhere from 5 to 12 blooms. As a cluster, they can grow to the size that’s bigger than your hand. This makes them bigger than what most hoya species will produce.

Of course, the most stunning part about its blooms are the slightly more pointed tips. They also have a striking maroon-purple color that has some pink and white mixed in there.

Although, the actual colors can vary from very dark red/maroon to more dull colors. Similarly some have pale pink or brown-pink hues.

Once they bloom, the flowers will last for about 2 to 3 weeks.

Finally, if you want the plant to blossom, here are two thing you should always keep it mind.

It needs a lot of bright, indirect light. Low light is not a good idea if you want the plant to produce flowers.
Don’t cut off the stalks (called peduncles) after the flower has faded. These are perennials so new flowers will grow from the same peduncles season after season.

Pruning

The Hoya Imperialis is both a creeper and a climber. However, if you see it as a houseplant, it will likely be training down from a hanging pot or basket.

If you decide to display it this way, make sure the pot or basket you use can take its weight as the plant grows. It will get big as it grows. And its vines will reach several feet long.

Also, as it gets fuller, it will be dense. This adds to its weight.

In generally, the Hoya Imperialis can get a bit messy as it gets longer and bushier. As such, you will need to it on a regular basis to keep it neat and tidy looking.

Similarly, pruning will allow you to control it length depending on how much space you have available.

In addition to hanging it up another great way to grow the plant is to give it something to climb on. This is how it naturally grows in the wild. So it will appreciate a support to go up on.

You can use a trellis, pole or strong wire and train it to go up.

How to Propagate Hoya Imperialis

The simplest way to propagate Hoya Imperialis is by using stem cuttings. You can use the stems you cut off when pruning the plant. As such, don’t throw these away.

Similarly, you can propagate the plant through air layering, separation and seed. Although because it roots quite well from stem cuttings, there’s really no reason to go through the extra work required by the other methods.

With stem propagation, you can likewise choose to root the cuttings in water or in soil.

Since the best time to propagate is around spring to early summer, it is a good idea to get ready for it ahead of time. This way you can plan your pruning session as well and just use the cuttings you get from there.

Here’s how to propagate Hoya Imperialis from stem cuttings.

Choose a healthy stem with at least 2 to 3 leaf nodes on it. Cut below the node and try to get at about 4-6 inches worth of stem so you have enough to easily submerge in water or plant into soil.
Remove the lower leaves to expose the leaf nodes. Keep the top foliage as they’ll help with growth (via photosynthesis).
Place the cutting in a container filled with water. If you want to see the roots as they grow, use a glass container.
Make sure the nodes are all submerged in the water. This is how they’ll root.
However, remove any foliage that will end up in the water. These will rot if kept wet for long periods.
If the cutting you got had aerial roots, squeeze these into the water as well. They’ll root much quicker than the nodes so you do want to take advantage of aerial roots if your plant grows them.
In a few days the water will eventually get murky. So, replace it before it does.
Keep the cutting in a warm, humid location with bright, indirect light.
Then, let it be.
In about 3 to 6 weeks you should see a good amount of roots. The would have also gotten longer.
Once the roots are about 2 inches long, you can pot it up into soil.

Besides propagating in water, you can also propagate the cutting in soil.

Here, instead of placing the cutting in water, plant it into a pot with moist, well-draining potting mix.

From there, the cutting will root and establish themselves.

How to Repot or Transplant Hoya Imperialis

When choosing a pot for your Hoya Imperialis, make sure it has some kind of drainage. This can be drainage holes at the bottom or if you want you can use a netted pot.

The holes will allow any excess moisture to get out of the pot after it is drained from the soil.

Once the plant outgrows its container, you’ll see roots coming out of these holes as well. This makes it easy to tell that the plant wants more space.

In generally takes about 2 years before you need to repot the plant.

Since it is a larger hoya species, the Imperialis will need a bigger pot. Depending you how big the plant is when you get it you’ll likely need a pot that is anywhere from 4 to 10 inches. Then move up every 2 years.

Is It Toxic/Poisonous to Humans, Cats & Dogs

The Hoya Imperialis is non-toxic to cats, dogs and humans. This makes it safe to keep around the house if you have the space. Similarly, you can keep in the patio, balcony or somewhere outside.

Wherever you decide to put it, at least you have peace of mind that it does not pose a poison or toxicity risk to your pets and kids.

Problems & Troubleshooting

Pests

Pests are a normal part of houseplant care. Unfortunately, they’re a huge hassle and headache that no gardener wants to deal with.

But, you can’t prevent them from happening.

As such, the only thing you can do is to regularly inspect for pests and treat them as soon as possible.

This is the case for the Hoya Imperialis.

And the most common pest that will likely attack it are mealybugs, which are white cotton-like bugs that like to feast on the sap of the plant.

Additionally, aphids, thrips and scale insects can also occur.

The important thing is to spot them early. They like to hide behind leaves and near the nodes. Also, they tend to target younger leaves first. So, check those as well.

Diseases

Diseases are less of the problem since the Hoya Imperialis is more resistant to them. However, one common mistake that many home growers do encourages diseases. That is too much moisture.

Excess moisture makes the environment favorable for pathogens including bacterial and fungal infections.

As such, avoid leaving the leaves wet for long periods of time. Also, try not to overwater the plant as this can lead to root rot.