The alluring Wax Plant is making a huge comeback

Hoya carnosa Picture courtesy Lorenzo Andrioli from flickrHoya carnosa Picture courtesy Lorenzo Andrioli from flickrHoya carnosa will never go out of fashion for long, for good reasons. Its waxy, evergreen foliage is attractive all year round, and it’s easy to grow, making it perfect for beginner gardeners. And when in full bloom, its clusters of flowers are so abundant, it’s sure to grab attention wherever it is grown. Read more about this tropical beauty below, and how to plant, propagate, and care for it as an outdoor, or indoor potted plant.

Hoya carnosa is an old-fashioned plant that your grandparents probably had, and you may even remember the plants adorning sunny indoor lounges and dining rooms. Wax plants were very popular from the 1960's to the '80s and then fell out of fashion for whatever reason. Like all industries, fashions in horticulture are driven by marketing trends which come and go almost seasonally, but some plants just can’t be ignored for too long because they are simply just too beautiful and rewarding to grow. Hoya carnosa is one of these plants that’s made its way back into the hearts of plant parents all over the world, and thankfully, also in South Africa.

Hoyas are named after Thomas Hoym, the Duke of Northumberland’s gardener, and the grower that brought attention to these unique plants. And although there are many species of Hoya, Hoya carnosa remains the most commonly cultivated species for home growing.

Hoya is the largest genus of flowering plants in the dogbane family (Apocynaceae), under the sub-family Asclepiadoideae. This family of tropical plants are native to tropical Asia and Australia, and as of April 2020, the World Checklist of Selected Plant Families, accepted over 520 species in the genus Hoya. There are also hundreds of cultivars, and hybrids, so naturally not all Hoyas are created equal and many of them have different traits and care requirements. Some are succulent, some are non-succulent, some are woody or shrubby, some are ephyphtic, some are terrestrial, and some, like Hoya carnosa are climbing vines with succulent leaves and woody stems.

The greatest diversity of Hoya species comes out of subtropical and tropical Asia through the western Pacific. The Philippines, Indonesia, Malaysia, and Papua New Guinea in particular, have a high diversity of Hoyas, but they can also be found in places like Thailand, China, Singapore, India, Bangladesh, Cambodia, Japan, Laos, Vietnam, Myanmar, Vanuatu, the Japanese islands of Kyushu and Ryukyu, the Fiji Islands, and Australia.

Hoya carnosa var. Compacta Picture courtesy epiforums from flickrHoya carnosa var. Compacta Picture courtesy epiforums from flickrHoya carnosa

Hoya carnosa is native to Queensland (Australia), East India, southern China (Fujian, Guangdong and Yunnan provinces, and Guangxi autonomous region), Taiwan, Myanmar, Vietnam, Malaysia, the Japanese islands of Kyushu and Ryukyu, and the Fiji Islands.

It grows wild in humid, lowland, tropical and subtropical rainforests, where the plant starts its life at ground level, gradually working its way upwards towards the light by wrapping itself around trees, and hanging down from magnificent heights; or it may scramble over rocks, growing and spreading continuously, reaching lengths of at least 6m. The wax plant is semi-epiphytic (not parasitic) and grows where rainfall is around 5,000mm per year, and humidity is high.

It produces large umbels of star-shaped flowers abundantly, and although the flowers are typically light pink, they may vary from near-white to dark pink, always with a red centre. The surfaces of the flower petals are covered with tiny hairs, giving them a fuzzy sheen and feel, and the blooms are sweetly and heavily scented, and may produce excess nectar that drips from the flowers. The scent of Hoya flowers tends to become stronger during the night which suggests that it may target night pollinators. In warm tropical and subtropical regions the vines can bloom sporadically throughout spring and summer, and the flowers are followed by spindle-shaped fruits.

The flowers are carried on woody spurs or penduncles about 2cm long, which arise from the leaf axils. Hoya spurs produce flowers year after year, so never remove them from the plant. Rather allow the flowers to dry and fall off naturally as removing the spurs will reduce the quantity of flowers produced in the future.

Hoya carnosa has been in cultivation for more than 200 years, giving rise to many gorgeous new garden cultivars that vary in foliage, form, or flower colour.

Click here to see Google images of Hoya carnosa

Hoya carnosa var. ‘Compacta’

Hoya carnosa var. ‘Compacta’ commonly known as the “Hindu Rope Plant” or “Krinkle Kurl” is very popular, and grown not only for its blooms but also for it’s unique, waxy, tightly packed and twisted leaves, which tend to grow closely together, creating a dense and compact appearance which resembles a knotted rope. The leaves are typically dark green, although certain cultivars may have variations in colour, such as variegated or speckled patterns. Because the vines can grow quite long, it’s wonderful in a hanging basket, or trained up a trellis. The flowers of this variant tend to take on a pinkish colour.

Click here to see Google images of Hoya carnosa var. ‘Compacta’

Hoya carnosa 'Tricolor' Picture courtesy Dan Jones from flickrHoya carnosa 'Tricolor' Picture courtesy Dan Jones from flickrHoya carnosa ‘Tricolour’

Hoya carnosa ‘Tricolour’ is also known as “Exotica” and “Krimson Princess”, and occasionally is confused with Hoya “Krimson Queen”. It has lovely pink stems and magnificent foliage that showcases a remarkable blend of green, creamy white and pink hues, making it a remarkable addition to any garden. The variegation patterns vary from leaf to leaf, creating a mesmerizing mosaic of colours. The creamy white streaks often encompass the edges of the leaves, transitioning into a vibrant pink towards the centre. It’s long, trailing vines can grow several meters in length, and will gracefully cascade from hanging baskets or tall pots, and when in bloom the clusters of bright pink flowers create an enchanting display.

Click here to see Google images of Hoya carnosa ‘Tricolour’

Hoya lanceolata subsp. bella

This is another species of Hoya worth mentioning, as it is also popular for beginners and collectors alike. It is a subspecies of Hoya lanceolata which doesn't grow quite as large, and is called the "Miniature Wax Plant" because the individual vines grow only about 46cm in length. The delicate, lance-shaped leaves emerge a beautiful light green, from lovely orange-pink stems, and when the plant reaches maturity it is a profuse bloomer, producing sweetly scented white flowers with violet coronas.

Click here to see Google images of Hoya lanceolata subsp. bella

Hoya australis Picture courtesy Lauren Gutierrez from flickrHoya australis Picture courtesy Lauren Gutierrez from flickrHoya australis

Hoya australis is known as the “Common Wax Flower” and is a native of the rainforests of Eastern Asia and northern Australia, and rather than growing beneath the canopies of trees it is mostly found on the rocky, outer edges of rainforests. To this day it is still the most commonly grown Hoya in all of Australia, and is also grown all over the world in all sorts of climates and conditions. Depending on the amount of light, the leaves vary between dark green and yellowish-green, and unlike some other Hoyas, it is more of a climber than a trailer, therefore it is best grow up a trellis or moss pole, rather than in a hanging basket. Hoya australis blooms in gorgeous clusters of white flowers that can have red or pink centres. The flowers usually show up in late summer or early autumn, but flowers can occasionally also appear in spring. The blooms produce a large amount of nectar that may drip, and their lovely fragrance is often compared to chocolate-vanilla.

Click here to see Google images of Hoya australis

Hoya kerrii Picture courtesy _J_A_D_S_ from flickrHoya kerrii Picture courtesy _J_A_D_S_ from flickrHoya kerrii

Hoya kerrii is a species that originates from the mountainous regions of China, and Java, one of the largest Indonesian islands. This climbing plant can grow up to 4m high, and its lovely thick, heart-shaped leaves have earned it the common nicknames, “Sweetheart Vine”, “Hoya Hearts”, and “Valentine's Hoya”. There are a lot of varieties of Hoya kerrii, many of which have variegated leaves. Hoya kerrii ‘Albomarginata’ has striking, white, variegated leaves; Hoya kerrii ‘Variegata’ has green leaves with a prominent yellow border; Hoya kerrii ‘Reverse Variegata’ is also called “Yellow Splash” because it has leaves with green borders that gradually turn yellow towards the centre. The blooms are typically pink or white and appear in summer. In Europe it’s often bought as a gift for Valentine’s Day, as a unique characteristic of this vine is that you can plant a single heart-shaped leaf into a small pot and keep it alive for years.  

Click here to see Google images of Hoya kerrii

Hoya kerrii Picture courtesy Babij from flickrHoya kerrii Picture courtesy Babij from flickrIn the Garden & Home:

Because this tropical beauty can only be grown outdoors in the warmest of climates, it is cultivated worldwide as an indoor plant, either in pots or hanging baskets. Outdoors it grows quickly, but indoors growth is slow to moderate, but no matter where you are growing your Hoya, as long as you follow a few simple steps, it will soon be pushing out new growth and climbing up anything it can wrap its vines around.

The wax plant is an absolutely stunning indoor plant, and because it doesn’t need a lot of upkeep to thrive indoors, is a terrific plant for children and beginner gardeners to learn indoor plant care. Its glossy leaves look attractive all year round, and when in bloom, what better place to enjoy the abundant display than in your home.

When styling your wax plant, always remember they love to climb and adding a trellis for the vines to clamber up will look beautiful anywhere. When your plant is still small, you can even just place it on a table - the visual effect of the foliage against any home décor is on the next level. However, bear in mind that the flowers sometimes drip sticky honeydew that could make a mess on furniture.

Hoyas are not only planted into pots, but are also available as a Kokedama, which can be translated as koke (moss) and dama (ball). This describes the technique of wrapping the roots and soil in moss to create a ball.  Kokedamas can be displayed indoors or on your patio, either by hanging them or placing them on a flat ceramic surface like a pot plant tray, plate or decorative bowl.

An added bonus is that studies done at the University of Georgia, and published in 2009, have shown Hoya carnosa to be an excellent remover of pollutants in the indoor environment.

Hoya lanceolata subsp. bella Picture courtesy HQ from flickrHoya lanceolata subsp. bella Picture courtesy HQ from flickrCultivation:

Caring for a wax plant indoors or outdoors is easy, and with a little attention and knowledge on how to care for it, it can live for 30 years or more, and because it’s also so easy to propagate, it can be passed down from generation to generation.

Because the wax plant is native to humid, tropical and subtropical areas, it is perfect to grow both indoors and outdoors in South Africa’s hot and humid regions. The optimum temperatures for wax plant care in the summer growing season are around 16 to 18°C at night and 27 to 29°C during the day.

It will tolerate lower temperatures, but if they drop below freezing the plant won't live for long outdoors, and temperatures around 10°C will force the plant into dormancy.

Outdoors, the plant will grow quickly, and the best place to plant it would be in a wind-protected area that provides bright, indirect light, and shelter from the hot sun. If your region is warm and frost-free but lacks humidity, spray the foliage down regularly with water to help create humidity, or plant it close to a pond or water feature.

If the wax plant is grown indoors, the most crucial step is patience because it grows slower and won't put out new growth until the root system is developed. It also takes around two years for the plant to mature sufficiently to produce blooms.

Hoyas are not only planted into pots, but are also available as a Kokedama, which can be translated as koke (moss) and dama (ball). This describes the technique of wrapping the roots and soil in moss to create a ball.  Kokedamas are very easy to maintain and can be displayed indoors or on your patio, either by hanging them, or placing them on a flat ceramic surface like a pot plant tray, plate or decorative bowl. Keep the plant out of draughts to avoid dehydration. When the Kokedama ball dries out, place it in a shallow plate filled with water, and leave it for a while to rehydrate then allow it to drain thoroughly before re-hanging it. To fertilise a Kokedama it’s easiest to use a foliar feeder for flowering plants, which is sprayed onto the leaves.

Click here to see Google images of Hoya Kokedama

The wax vine is easy to care for in most home situations provided it gets plenty of indirect light and around 50% relative humidity. In dry regions, placing a humidifier in the room will help greatly, as will misting the leaves down regularly with tepid water. To increase moisture around the plant without getting its roots sodden, you can also stand the pot in a saucer filled gravel and water. The gravel will elevate the pot to ensure that the pot is not standing directly in the water, and as it evaporates, the water adds humidity around the foliage. Keep your plant away from heaters and AC units whose air will dry out your plant's foliage. And in winter, ensure that it is not standing in a cold draught.

Since most Hoya species grow in the gaps of forests, they are more accustomed to getting dappled or diffused light, and in the home we should try to recreate that by placing the plant in bright indirect light. The plant also grows well under grow lights or other artificial light sources.

The wax plant loves growing in natural light next to a window, and can take some sun, but be careful because too much direct sunlight can burn the leaves. Some people like the reddish colour on the leaves which occurs when the plant becomes a bit sun-stressed, but once again, you just have to watch out that the leaves are not burning. Cultivars with variegated leaves will lose the vibrancy of their foliage if the light is not sufficiently bright.

Hoya plants require a well-draining soil that is rich in nutrients and which retains moisture but does not remain waterlogged. Loose soil that's aerated is what they want.

Traditionally peat-based soils were used to grow Hoya plants because peat is well-draining and provides good aeration. This type of soil also has a slightly acidic pH, which is ideal for Hoya plants. However, peat moss is no longer a sustainable material, so you may want to consider using a peat-free alternative. Peat moss alternatives like Coconut Coir, also known as Coco Peat or Coir Peat, are rapidly gaining popularity.

In its natural habitat the wax plant is semi-epiphytic, attaching itself on other plants to clamour upwards, therefore wood-based materials like orchid growing mixtures are an excellent choice for Hoya plants because they mimic their natural growing conditions. This type of soil also provides excellent drainage and aeration. It is important to note that orchid bark mixes can be quite chunky and may not be suitable for smaller Hoya plants, so for small plants, select a fine orchid mix.

A cactus mix is another good choice for Hoya plants because it is designed to retain moisture without becoming waterlogged.

As long as you fertilise your Hoya regularly, you can even mix equal quantities of vermiculite and perlite together to grow in. This is an excellent option because it is lightweight and provides excellent drainage and good aeration for the roots. Vermiculite holds nutrients like calcium, magnesium and potassium for a long time and slowly releases them to potted plants. It's therefore a great option for preventing nutrient deficiency in potted plants.  Perlite is not a fertiliser, and has no nutritional or microbial value for plants, and is used to keep the soil structure loose and light.

Using a good quality potting soil is also fine but it's better to lighten it up with lots of vermiculite or perlite. Mixing equal quantities of potting soil and orchid bark will also work well. 

You can even create your own potting soil by mixing together your choice of the ingredients mentioned above. Regardless of the type of soil you choose, it's important to ensure that it is well-draining and that it provides good aeration for the roots.

Wax plants aren’t particularly heavy feeders but they do appreciate some extra micronutrients and macronutrients, so to ensure that it receives all the nutrients it needs to thrive, it's a good idea to fertilise your plant regularly during the growing season. You can use a slow release fertiliser or any balanced feeder designed for flowering indoor plants. Feeding is not required during the winter months.

Once you've ensured your plant is in the right environment and soil type, all you have to worry about is watering. Because the wax plant stores water in its fleshy leaves, it performs best when the soil is allowed to dry out between watering’s. And although it’s always better rather to underwater than overwater, in summer the plant will naturally require more water than it will during the cooler winter months. Even if you forget to water to the extent that you notice that the plant is drooping, this is better than overwatering, and after a good soaking it will quickly perk up. But if you overwater this can lead to root rot, and the death of the plant. On the other extreme, if the plant seriously lacks water for too long, the roots will dry out and die back.

To encourage blooming, many gardeners recommend a short dry period of around 4 to 5 weeks in spring, this, together with good lighting, will likely encourage the plant to flower more.


Young wax plants need no pruning at all, but as the plant matures you may want to do an occasional light pruning to shorten very long vines and tidy up the plant a bit - think of it as a trimming as opposed to a haircut.

With age, and under optimal growing conditions the wax plant can sometimes grow very large and unwieldy, so if you need to give your Hoya a haircut and not just a trim, then that’s fine. If you do not prune too harshly and remove no more than one-third of the plant’s foliage at any one time, the plant will quickly put on fresh new growth.

You can prune your Hoya anytime in spring or summer, but pruning after the first flush of spring flowers is a good time, before the plant starts its most vigorous growth period.

Before cutting, first step back and look at your plant to assess which vines need to be removed completely and which ones just need to be trimmed back a bit. Look for vines where the penduncles, sometimes referred to as spurs, have fallen or broken off, and cut these vines right down.

A peduncle is the stalk that joins the base of a solitary flower or fruit, or a cluster of flowers or fruits, to the main stem above a bract, leaf, or node. For example, a peduncle holds a cluster of grapes, but each individual grape is held on a pedicel.

Like most species of Hoya, Hoya carnosa flowers from specialised perennial peduncles. These appear from the axils of the leaves and stem, and flowers may not be produced when the spurs first appear, but in time buds emerge from their tips. New flowers are produced on these same spurs every year, so they should not be removed.

Click here to see Google images of Hoya woody spurs or penduncles. 

If productive younger vines are growing too long they can be trimmed back with no harm, and this will encourage branching. When pruning, be very careful not to damage the remaining spurs. Prune by snipping the vine off just below a node (small swellings at the junction between the vine and a leaf).

If you are a bit nervous about pruning your plant, do the 1st round on the conservative side, you can always take off more growth the 2nd time round, but you can’t put it back on! If you do not prune too harshly the plant will quickly put on fresh new growth, and new flower spurs will grow on these new vines, resulting in even more flowers.

Note that when you are cutting the stems, sticky, white latex will often spew out, so protect your eyes, use gloves, and clean your pruning shears well afterwards.


There is a persistent piece of folklore which says that Hoyas prefer to be pot-bound, and if they are kept in a small pot, this will hasten flowering. Whether or not this is true is debatable, but we do know that Hoyas, like many other potted plants, prefer to be transplanted gradually into bigger and bigger pots as they mature, rather than being planted in an overly large pot to start off with. So, if you are transplanting your wax plant, choose a pot that is just slightly larger than the root ball. Unglazed terracotta pots are perfect for your Hoya as they are porous, allowing the soil to breath and dry out more efficiently. 

Because Hoya carnosa is used to growing epiphytically, it doesn’t need to be re-potted very often, and if you just refresh the substrate every year by adding fresh potting soil to the top layer of soil, it will only need re-potting every second or third year.

Repotting is usually done in spring, or directly after flowering. Select a new pot which is only slightly larger, remove the plant and gently shake off some of the excess old soil before placing it in its new pot and filling in with fresh potting mix. Water well after potting and then water as usual.


Hoya plants are easily propagated by cuttings, and to get a cutting, you will need to locate the nodes, which is the place where the leaves grow from the stem and where the new roots will grow from. Cuts should be done between these nodes and include at least a pair of leaves or nodes.

Cuttings will often root easily in plain water (use rainwater for best results). They will also root readily if inserted into an open potting medium that allows some air to get to the roots. It is important to allow the cut to dry out before it is potted, as this lessens the chance of root rot.  Dipping the cut end into a rooting hormone will speed up the rooting process but is not essential.

In about two years, the cutting will result in a plant capable of blooming. This ease of propagation makes growing Hoya vines to give as gifts to family and friends almost effortless, and enables you to pass along this amazing plant. 

Problems, Pests & Diseases:

Hoyas are fairly resistant to pests, but can sometimes be susceptible to mealybugs, aphids, spider mites, and scale.


Mealybug colonies often appear at the base of plants and leaves looking like small tufts of white fuzz. They are not always noticed in the garden because they like to hide under branches, twigs or leaves, on the shaded and secluded parts of plants.

Mealybugs are actually un-armoured scale insects that are found in tropical, moist, and warm habitats. These insects are small pink, slow-moving oval insects that are covered with a white, cottony wax, and they can infest all plant parts, including the roots.

Mealybugs are common on indoor pot plants, and outdoors they will occur more frequently in small, enclosed gardens that are sheltered from wind. They are often only noticed in summer, but winter is an ideal breeding time for them, so do an inspection of your plants in both winter and summer.

Infected plants will show stunted growth, yellowing of the leaves, distorted plant tissue, and leaf drop, and serious infestations can devastate many ornamentals. Yellowed or wilted foliage may also indicate an underground mealybug infestation.

Once you notice any sign of mealybug, immediate measures must be taken to get rid of them. Mealybugs are treated in the same way as scale insects, and as with scale, you can typically control small populations by removing any badly infested plant material, and then washing them off with a strong jet of water, or rubbing the colonies off the leaves with a soft brush or cloth.

Hydrogen peroxide 9% can also be useful as part of a treatment program for mealybugs, and spraying with any product containing canola oil and natural pyrethrins will kill adults on contact.

Biogrow’s Neudosan is a wonderful preventative spray, as are Bioneem and Pyrol. Alternating between Bioneem and Pyrol is great for preventing outbreaks of pests in both winter and summer. Margaret Roberts Organic Insecticide is another effective eco-friendly choice, and Oleum is a mineral oil which controls mealybugs, aphids, scale and red spider, as well as many other common garden pests.

If you suspect mealybugs in the soil, you can drench the soil with systemic products like Koinor.

Members can click here to read more about mealy bugs

Click here to see Google images of Mealybugs on Hoya


Aphids are soft-bodied and pear-shaped with a pair of cornicles (tailpipe-like structures) projecting from the rear end of their abdomen, and the adults may, or may not, be winged. There are many species, and they come in various colours, like light and dark green, black, brown, pale yellow and grey. They attack a vast number of garden plants, causing malformed or distorted growth, and can commonly be found near flowers, as they are attracted to their nectar.

Infestations can occur at any time of the year but are more common in spring because aphids love young, sappy plant growth. They must be controlled, as they spread viral diseases from plant to plant. Stunting and deformation of plant parts are common symptoms of aphid infestations.

If infestations are not severe, you can use sharp sprays of water to hose them off, or you can treat them with organic sprays like insecticidal soap, or sprays containing canola oil, with or without garlic, or only fatty acids, as these will only kill soft bodied insects and not beneficial predators.

Biogrow’s Neudosan is a wonderful preventative spray, as are Bioneem and Pyrol. Alternating between Bioneem and Pyrol is great for preventing outbreaks of pests like aphids. Margaret Roberts Organic Insecticide is another effective eco-friendly choice, and Oleum is a mineral oil which controls aphids and many other common garden pests.

Members can click here to read more about Aphids

Click here to see Google images of aphids on Hoya

Spider Mites

Spider mites seem to miraculously appear during hot and dry summer spells, and shelter in the little microclimate created underneath the leaves of plants, where they lay their eggs. Populations can explode during hot, dry weather, and the mites are so minute that most people don't even see them. If you look closely, or with a magnifying glass, the alert observer may see many tiny, reddish creatures the size of small pin heads, scurrying to hide themselves. Other signs of infestation are fine white spider webs on the plant, a mottled, silvery look to the top of the leaf, or a severe yellowing or bronze colour to the leaves, leaves dropping off, and leaf curl.

Red spider mite is a very common pest of many ornamentals, and if they are subjected to the mite bites even the flowers may be distorted when they start emerging. Mite damage to the open flower causes a browning and withering of the petals that resembles spray burn.

Regular plant inspection helps to control a mite infestation before it gets out of hand, so check your plants often. If you spot them early, first cut off and dispose of the worst infected leaves, and if your Hoya is growing outdoors, drench the entire plant, but especially the undersides of the leaves, using a strong stream of water from a hose pipe. Indoors you could use a pressure sprayer to do this. Doing this regularly during this type of summer weather will go a long way in controlling these pests. And, if their shower is followed by an insecticidal spray, this would be doubly effective at keeping mites at bay.

Because red spider mites quickly adapt to chemical threats, quickly building up immunity to many pesticides, alternating your sprays can be very effective. During hot and dry weather, try alternating between sprays of Bioneem and Pyrol at 10 to 14 day intervals. Margaret Roberts Organic Insecticide is also good to use against red spider mites, as well as Oleum.

Biogrow ‘Bioneem’ comes from the Neem tree and because the key insecticidal ingredient found in the neem tree is Azadirachtin, a naturally occurring substance. It is used to control a wide range of insects, (up to 200 types) including red spider mites, mealybugs, aphids, and scale. Biogrow ‘Vegol' controls many garden pests including spider mites, aphids, mealy bugs and scale. It is 96% Canola Oil and is a contact insecticide with ovicidal activity that can be used in both the dormant and growing seasons, and does not persist in the environment. Biogrow Pyrol has naturally occurring plant oils as its active ingredients and kills all stages of insects.

There are many natural DIY recipes you can easily make at home to treat red spider mites, using everyday kitchen ingredients like Canola Oil, Hot Chilli Peppers, Cayenne Pepper, and Garlic.

Members can click here to read more about Spider Mites and find DIY recipes to treat them. 

Click here to see Google images of Spider Mites on Hoya


Scales are tiny parasitic insects that adhere to plants and live off the plant's sap. They look like bumps and are often mistaken for a disease. There are some 7,000 species of scale insects, varying greatly in colour, shape and size. Scale insects infest many species of trees and shrubs, and often go unnoticed, but they can do damage out of all proportion to their size. They can quickly infest leaves, twigs, branches and fruit, and are found all year round.

Scale is more prevalent in shady or protected places of the garden than in open areas. They can be hard or soft, and like aphids, mealy bug and Australian bug, scale insects secrete honeydew which attracts ants. Ants crawling up and down the plant are a sign of possible scale infestation.

Spraying with organic insecticidal soaps like Biogrow Neudosan works well for scale and provides quick results and instant pest protection. Bioneem is a powerful insecticide made from natural ingredients derived from the seeds of the Neem tree. Its key ingredient is Azadirachtin, a naturally occurring substance. Oil based formulations like Margaret Roberts Organic Insecticide will suffocate the insects; Biogrow Pyrol has naturally occurring plant oils as its active ingredients and kills all stages of insects; and Oleum is a white oil emulsion insecticide which will also control scale.

Members can click here to read more about Scale

Click here to see Google images of Scale on Hoya

Troubleshooting Your Hoya

Below are some common signs that will explain what may be plaguing your plants:

Hoya leaves are turning red or burning

Leaves taking on a reddish hue is a sign of sun stress, and is often a desired trait with gardeners. However, if you notice that the leaves are burning then the plant is receiving too much direct sunlight and should be moved.

Hoya leaves are shrivelling

Shrivelling leaves may indicate that your Hoya if not be getting enough water, and there may be die-back or an issue with the roots. Lack of humidity may also be the cause, or it could be sign of mealybugs or root mealybugs. Check your plant to assess what the situation may be.

Hoya is starting to look limp

This is commonly an indication that the roots have rotted back completely, due to overwatering, but on the other hand, it could also indicate a lack of watering. Check the roots and if overwatering is the cause, then take some healthy cuttings to propagate the plant, as the plant will most likely collapse completely and die.

Hoya internodes are greatly extended

Extended internodes indicate that your Hoya is stretching out in search of more light and needs to be moved closer to a brighter light source.

Hoya hasn’t flowered

If your Hoya doesn’t flower this is usually the result of insufficient light and it needs to be moved closer to a brighter light source.  

Buds fall off before bloom

Aborted buds can occur when the potting medium is either too dry, or too wet, for too long. Do not move the plant when buds are forming because changes in light may cause them to drop. Raising the humidity can also help.

Leaves fall off abruptly

Leaf drop is often the result of the plant standing in a cold draft or chill. Ensure that your Hoya is in a warm, humid location.

Hoya has sticky sap on the leaves

If your Hoya is not in bloom and has sticky sap on the leaves, this is an indication of sap-sucking insects which need taken care of accordingly (see Pest section above).


While many plants in the Apocynaceae family are poisonous, the Hoya is not dangerous and is deemed safe around adults, children, birds, dogs, horses and farm animals.

While these plants are not poisonous or harmful to touch, some people and animals may have a reaction to consuming them. This can especially be a problem if a large amount is ingested, so it’s always best to keep plants out of the reach of curious pets and kids. Again, the reaction won't be deadly but can cause vomiting.

Hoyas carnosa produces a milky sap laden with latex which is considered toxic. Anyone with an allergy to latex should avoid handling the plant if it is damaged. When you are cutting the stems, the latex will often spew out, so protect your eyes, and use gloves.