Hoya Imperialis Care Infographic
Hoya Imperialis Care Infographic

Hoya Imperialis works as a great air-purifier which makes it one of the most loved plants among urban gardeners. It absorbs many harmful toxins from the air such as benzene, formaldehyde, and toluene.

From our holistic care guide, learn all about growing and caring for this beautiful Hoya species. 

What Is Hoya Imperialis?

Hoya Imperialis is a fast-growing, epiphytic, climbing vine native to the rainforests of Southeast Asia. It is one of the most widely cultivated Hoyas because of its large flowers. Hoya Imperialis belongs to the Apocynaceae family. Some of its commonly known names are the Wax plant, Waxflower, and Wax vine.

Hoya Imperialis Care

Hoya Imperialis Red is a rampant grower and if you are planning to grow it indoors, think again as it gets quite big. The plant does not have high growth requirements when it comes to water, soil, and fertilizer but it tends to get a bit fussy at times. Read the growth requirements below to know how exactly you can grow the Wax vine.

– Water Requirements

Hoya Imperialis has relatively higher water needs than most other Hoya varieties. It needs the soil to be constantly moist but not water-logged. Overwatering causes the soil to be damp and makes the plant susceptible to root rot and fungal growth.

Water it once a week in summers and once in two to three weeks in the winter months. This frequency will vary depending on the weather conditions in your area. With low humidity and higher temperatures, your plant will need more water and vice versa. 

Hoya Imperialis pink flower on green mossyIt is advised that before watering your Hoya, check the soil by using the finger-knuckle test to determine whether the plant needs to be watered.

Insert any one of your fingers till the second knuckle. If it comes out dry and the soil does not stick to your finger, water the plant.

Another great way to prevent overwatering is by lifting the pot every time you plan on watering the plant. If it feels heavy on lifting, the soil has probably not dried out. Younger plants are more at risk of rot than mature ones. So be careful while watering this Hoya.

Always water Hoya Imperialis deeply to avoid mineral salt build-up in the soil. Watering the plant thoroughly is better than watering in sips as the mineral salts in tap water accumulate on the topsoil and do not drain out of the drainage holes.

– Light Requirements

Hoya Imperialis grows well in full to partial shade where it can receive lots of bright indirect light. A bright shaded spot where the plant can receive morning and evening sunlight works well for its growth.

If your home does not receive enough natural light, you can grow your Hoya under artificial grow lights. 10 to 12 hours of light from grow lights work well for the plant’s growth. A South-east or South-west facing window works well in providing the appropriate light. 

Hoya Imperialis has rich, glossy green leaves when they receive enough sunlight. If you think it is a Hoya with red leaves, then you are wrong since Hoya Imperialis has reddish blooms which are also called Hoya Imperialis Red.

– Soil Requirements

Hoya Imperialis soil mix should be the one that drains well and is rich in nutrients. It is an epiphyte which means that there is no need to grow it in the regular potting soil as it needs a soil mix with excellent drainage and cannot tolerate waterlogged soil for too long. 

If you are preparing the soil mix at home, mix lots of orchid bark chips, coco husk, sphagnum moss and perlite. All these thick materials will provide excellent drainage and moisture retention to the soil. 

What Hoya Imperialis needs in its soil is – good water retention, excellent drainage and aeration. This means as long as you can fulfill these needs, you can prepare any rich soil mix and modify it according to your needs. 

– Temperature Requirements

There is not much clarity about the optimal temperature range for the Hoya plants. But Hoya Imperialis grows well in the temperature range of 60 to 85 degrees Fahrenheit. Avoid exposing the wax plant to temperatures lower than 55 degrees Fahrenheit as it is not frost and cold-hardy. 

Hoya Imperialis finds the usual room temperatures indoors comfortable. Growth may slow down a bit in winters but the plant will survive the cold weather conditions when kept indoors. In summers, if the temperatures in your area increase a lot, mist the plants occasionally to maintain the moisture levels. 

– Humidity Requirements

Being a tropical plant, Hoya Imperialis has high humidity needs. It grows well in humidity levels above 60 to 70 percent. Try to maintain humidity above 50 percent for healthy growth by keeping humidifiers or humidity trays around the plant.

Make sure to keep good air circulation around the plant with high humidity. Lack of air movement makes the plant susceptible to root rot and fungus growth. High humidity with good air circulation is the key to keeping this plant happy.

– Fertilizer Requirements 

Feed Hoya Imperialis with an orchid fertilizer during the active growing seasons of spring and summer. Additionally, you can use a balanced, liquid fertilizer weekly to encourage healthy growth. Try to use organic fertilizers over the chemical ones. 

Fertilizing during the active growing period helps activate healthy leaf growth and keeps good health of the plant. We recommend using liquid fertilizers over others because they are easier to dilute and do not cause salt build-up in the soil. 

Use lots of organic matter in your soil mix to avoid the use of chemical fertilizers. Avoid overfertilizing the plant as it also causes salt build-up and burns the roots. In winters, do not fertilize at all and let your plant sit as it is until spring. 

– Pruning 

Hoya Imperialis is a fast-grower and can grow rampantly over anything that comes in its way. Prune the extra leaves and stems to maintain their size. Regular pruning helps in keeping it compact without taking up much space indoors.

Aside from pruning repotting or transplanting Hoya Imperialis is only needed when the plant outgrows the container every few years. It takes about two years for the plant to outgrow the pot. Prune the dead flower heads and leaves and remove the plant from the pot. 

In a freshly prepared peat-based soil mix, keep the plant and firm the soil around its roots. You can also trim the roots before repotting the plant. Keep it in a shaded spot and let it adjust to the new surroundings. Remember to keep the soil evenly moist.



Hoya Imperialis can be propagated using stem cuttings and layering. The stem cuttings develop roots quickly and can reach the flowering stage in just two years. Layering is more difficult than the stem cutting method as it is difficult to layer the stiff branches.

It can also be propagated from seeds but this method is used by experts and the seeds do not store well. 

– Stem Cuttings

To propagate Hoya Imperialis using the stem cuttings, take a four to five inches long cutting with two to three nodes. Allow the cutting to callus for a day, after which you can dip it in rooting hormone powder the next day but you can skip this step. 

The next day, you can place this cutting directly in the propagation tray and shift it to the soil when the roots are about an inch long. Wait until spring or summer to choose a healthy cutting from the plant. Make sure that the main plant from which you take a cutting is free of pests. 

Keep the soil evenly moist and do not let it dry out completely until the plant fully establishes itself. You can group the plant with other plants to maintain humidity and temperature. 

– Stem Cuttings in Water

Once the stem cuttings callus in a day or two, you can place it in a jar of water where it can root. Do not dip it in rooting hormone and simply put it in water such that the top leaves remain above water and only the nodes are dipped. 

After a couple of weeks, once the roots are about an inch long, shift them to the soil and grow in evenly moist soil. Keep the newly planted cuttings in a shaded spot for the initial days and give them time to adjust to the new surroundings. 


Although Hoya Imperialis is an easy plant to care for, it can face some problems that might give you a hard time. Let us look at some of them in detail.

– Plant Not Flowering

One very common problem that most people face while growing Hoya Imperialis is the plant not producing enough flowers. The main reason behind this is that your plant is receiving very little light. It could also be due to a lack of nutrients in the soil. 

First and foremost, move your plant to a bright location where it can receive lots of indirect light. Nonetheless, you can also try to creep it horizontally to trick it into believing that it is time to flower. Feed the plant with a well-balanced, liquid fertilizer for flowering.

– Shriveling and Falling of Leaves

Falling and shriveling of leaves could indicate a possible mealybug infestation. Check the leaf undersides and look for these tiny, sap-sucking insects. They are mostly attracted to succulent-like plants.

If the mealybugs suck too much sap from the plant, the plant may even die. They also secrete the sticky honeydew that causes sooty mold. Prevent mealybug infestations by checking the plant before buying and avoid over-fertilizing the plant as they are attracted to nitrogen-rich fertilizers. 

Use isopropyl alcohol-dipped cotton swabs to apply to the affected portions. Dilute the alcohol with water to avoid leaf damage, it is advised to prune the infected parts and use insecticidal soap for more severe infestations. 

– Spider Mite Infestation

Spider mites can be a major issue if you live in a dry area. They thrive in dry weather conditions; however, if you notice white, dusty, web-like coverings on the leaves and stems, your plant is probably infected by spider mites. 

Wash down the leaves and stems with a blast of water to get rid of the mites. Do it in a well-ventilated spot in the evening. Use chemical treatments in case of more severe infestations.

– Discoloration and Falling of the Foliage

If you notice the plant leaves falling off and losing color, it could be due to a sudden cold exposure. In the winter months, bring your plant indoors to a bright, warm spot where it can receive filtered sunlight. 

The plant growth slows down in winters but it will survive if you keep it indoors. It is essential to keep the plant warm, especially if temperatures fall significantly in your area. Exposure to frost can be even more dangerous than cooler temperatures.

Frequently Asked Questions

Let us take a look at some of the most commonly asked questions about Hoya Imperialis.

– Is Hoya Imperialis Toxic?

Hoya Imperialis is non-toxic to pets and children and is perfectly safe to keep indoors around them. But avoid contact with the milky sap as it can cause skin irritation to some people. Keep them at an arm’s length from kids to avoid such risks.

– What Is the Growth Rate of Hoya Imperialis? 

Hoya Imperialis is a fast-growing plant that can get difficult to control. It can grow up to 10 feet long rampantly climbing over whatever comes in its way. In its natural environment, the plant grows quite rapidly and gets nutrients from the soil, air, and decaying tree barks.

If you are planning to grow this trailing plant indoors, keep in mind that it grows fast and can cover a lot of space if left unpruned. The best way to grow the vine is to let it freely grow on a patio or other open area where it can grow with the support of other things.

If you want to grow it mounted in a pot, stake the pot with a trellis and hold up the stems with clamps or tapes. Since the stems become stiff as they get older, you have to twist the new ones back into the trellis as soon as they grow.

– Do Hoya Imperialis Like Terracotta Potts?

We recommend growing Hoya Imperialis in terracotta or clay pots as they are better at absorbing the excess moisture from the soil than plastic and ceramic containers. Using terracotta planters is better if you are a beginner. Once you get a hang of when and how much to water, you can shift to plastic pots.

Apart from choosing clay pots, make sure you grow Hoya Imperialis in a pot that matches the size of the plant. A smaller pot limits the amount of water available to the roots. A large planter puts the plant at risk of root rot by making more water available to the roots.

– Does Hoya Imperialis Have Flowers?

Hoya Imperialis has pretty-looking, star-shaped, red waxy flowers that bloom throughout the year. These large flowers can get three to four inches wide with their color varying from maroon to mauve. The flowers bloom in clusters known as umbels. 

Under optimal growing conditions, the plant can produce a large number of umbels carrying the gorgeous red waxy blooms. The blooms have a sweet and spicy fragrance. 

It is hard for Hoyas to bloom indoors. So if you want your Hoya to produce flowers, shift it outdoors to a well-lit and warm spot. Sometimes, it is seen that Hoya Imperialis blooms even in colder months under grow lights. 


Hoya Imperialis Air PurifierIf you are looking for a vine to fill space, grow rapidly, and also purify the air, Hoya Imperialis is the one for you. Let us summarize all the essential care tips once more. 

  • Hoya Imperialis or the Wax plant is a fast-growing epiphyte native to Southeast Asia. It has pretty, waxy blooms ranging from mauve to maroon in color. 
  • Under the right growing conditions, it can grow quite fast and take up a lot of space due to its rampant growth.
  • It needs bright light, airy and draining soil, and lots of water to grow well. 
  • The soil should be rough and chunky with excellent drainage and moisture retention.
  • Repot Hoya Imperialis once every few years when it outgrows the pot and propagates the plant from stem cuttings in soil and water.

Add the gorgeous Malaysian vine with these otherworldly lowers to your garden now to add some uniqueness to your garden.

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