Hoya australis is a variety of hoya plant native to Australia and parts of East Asia. This plant is also known as the honey plant, porcelain flower, and wax vine. Overall, Hoya australis plant care is pretty simple, but getting your plant to flower can take a little more work than simply keeping the plant alive and growing.
This member of the Apocynaceae family is known for being long-lived, and also for its waxy, chocolate-scented flowers. The leaves are glossy and oval-shaped with a slightly waxy texture. New leaves start with a snazzy red tint that fades to green as the plant matures.
There are over 200 species of hoya in all! This climbing, epiphytic vine typically grows on other trees or even rocks in tropical rainforests, and can reach up to 30 feet tall in the wild. Indoors, vines will stay around 10 feet long.
This quirky plant is beautiful and easy to care for. Here’s everything you need to know about helping your Hoya australis thrive.
How to Care for Hoya Australis
Soil and Potting
Drainage is key for keeping this plant healthy, so be sure to choose a potting mix that is light and drains quickly. Cactus or indoor potting mix with extra perlite and orchid bark mixed in can do the trick.
We also highly recommend our Premium Monstera Potting Soil because it drains beautifully while also retaining just enough moisture to keep these tropical epiphytes happy. It’s ready to go right out of the bag with no soil amendments whatsoever. It will also stay nice and aerated for a very long time, which gives the roots plenty of space and air pockets to stretch out and breathe!
While the roots like air pockets in the soil, they don’t need a lot of room in the pot. Choose a pot that’s just an inch or two larger in diameter than your hoya’s root ball. And make sure the container has drainage holes!
Your hoya isn’t picky about pot materials, but if you tend to love your plants to death by watering too much, terra cotta might be a good choice because it has a moisture-wicking effect, which can help protect against overwatering.
You can either give your hoya something to climb—like our favorite minimalist trellis set or a moss pole—or you can let the vines trail. This plant will be happy in a hanging pot or as a shelf or tabletop plant where its vines can trail outward or downward.
As a tropical rainforest plant, Hoya australis likes plenty of bright, indirect sunlight. For most locations, this means an east-facing window where your plant will get a little soft, direct morning light, and lots of bright but not direct light the rest of the day.
Do not put your hoya in the harsh, direct afternoon or midday sun because it will scorch the leaves. If you must put your plant near a south- or west-facing window, make sure to filter the light with a sheer curtain, or move the plant back far enough that it still gets plenty of bright light—but no direct light!
While Hoya australis can survive in lower light conditions, it won’t flower or grow very quickly if its conditions are too dim. A north-facing window may not provide enough light for this plant to thrive.
However, if you aren’t able to provide enough natural light, your plant will do well with a grow light. Try these full-spectrum grow bulbs that you can screw right into ordinary light fixtures! Give your plant 8 hours of this light per day.
This rainforest plant loves warm, tropical temperatures! Keep temperatures between 65-85 degrees Fahrenheit, and don’t let them drop below 60 degrees. Your plant may appreciate a cooler period when it’s getting ready to flower, but we’ll cover that later.
Watch out for drafts that can freeze your leaves, and heaters or fireplaces that can scorch them.
Remember, this is a rainforest plant. Rainforests are humid places, so your Hoya australis will be healthiest with humidity levels above 40% (with 60% being its happy place).
If you live in a tropical or semi-tropical area and don’t use a lot of indoor climate control, you might be good to go. But if you live in a more arid environment and/or run the heat or air conditioning frequently, you might have a hard time maintaining these humidity levels.
Luckily, there are plenty of tricks for raising the humidity levels right around your plant.
If you have a bright, steamy bathroom, your hoya might be very happy in there! You can also group your plant with other houseplants; as these plants respire, they’ll raise the local humidity slightly, and they’ll all benefit.
You can also set up a humidifier near your Hoya australis to give it a little humidity boost.
Humidity trays are a popular solution to provide plants with more humidity, but this might not work for a trailing hoya, especially a large one. You could set up dishes of water near your plant, which will create a little extra humidity as the water evaporates.
You could also combine some of these tricks for the best results!
One thing you definitely DON’T want to do is overwater your Hoya australis. These plants are pretty tough, but they can develop health problems quickly if they sit in soggy soil for too long.
That being said, it’s important to keep an eye on the moisture levels of your Hoya’s potting mix so you’ll know when to water. As a general rule, you should water when the top 2-3 inches of soil feel dry to the touch, or when a moisture meter reads 3-4. If your plant is going through a dormant period, you could even let it dry out a little more.
(We really like this moisture meter because it measures soil pH as well as light levels!)
The leaves can also tell you if the plant is thirsty because they’ll get a little wrinkled and even fold up if they’re dehydrated. As long as you catch this quickly, they’ll be as good as new once they rehydrate and turgor pressure is restored.
We recommend letting your plant tell you when it’s thirsty rather than watering on a schedule because your Hoya’s watering needs can vary greatly depending on the time of year and other factors in its environment, including light levels, the humidity, and whether it’s actively growing or not.
When your plant is ready to be watered, add water to the top of the soil until it starts to drain out the bottom of the pot. Let it drain completely in a sink or bathtub, or make sure to empty the drainage tray right away.
Hoya australis might also respond well to bottom watering, but take care not to get the leaves or vines wet.
Another thing to remember about watering Hoya australis is that this plant can be sensitive to the minerals and chemicals in tap water, so it’s a good idea to use rainwater or distilled water. You can also simply leave tap water out overnight to give those chemicals a chance to evaporate a bit before watering your plant.
Fertilize your Hoya australis regularly during the growing season (spring and summer) with a gentle, balanced liquid fertilizer that’s properly diluted. If you’re trying to get your hoya to bloom, you might want to use a fertilizer that’s a little richer in phosphorus to support flower production.
We recommend Indoor Plant Food for regular fertilization because it’s gentle enough to use with every watering without burning your hoya’s roots or causing nutrient excess or deficiency. That way, you won’t have to remember a fertilization schedule!
You can stop fertilizing completely during the winter when your hoya isn’t likely to be actively growing. Simply hold off during the colder months and resume fertilizing in the spring.
One of the best parts about Hoya australis is its beautiful flowers! And as far as flowering plants go, this one blooms pretty readily indoors.
Once the plant is mature (this takes about 5-7 years), Hoya australis blooms in gorgeous clusters that are several inches wide and contain many tiny white flowers that can have red or pink centers. These flowers usually show up in the late summer or early fall, but Hoya australis can also occasionally bloom in the spring. Their lovely fragrance is often compared to chocolate!
If you want your Hoya australis to produce flowers, it’s imperative to provide enough bright, indirect sunlight. Also, make sure to avoid moving your plant if you’re trying to get it to bloom, or when it’s already flowering. It also helps to reduce the temperatures to the low 60s during the night to encourage blooming.
Hoya australis’s roots don’t get crazy, so you’ll only need to repot every 2 years or so, or when your plant gets root-bound. When you do repot, get a pot that’s just an inch or two larger than the old one.
Hoya can be sensitive to environmental changes like repotting. When you do need to repot, carefully tip the pot on its side and gently pry the roots out with a trowel or butter knife. Do NOT pull on the vines to uproot the plant. It can also help to water the plant the day before repotting so the roots are softer and easier to unpot.
Don’t fertilize your Hoya for a month or two after repotting because the roots will be extra sensitive and prone to chemical burn.
Hoya australis doesn’t enjoy being pruned, and pruning doesn’t generally stimulate new growth. You shouldn’t need to prune in order to control its size because you can simply wrap the vines around the pot or support if they get a little long.
If you notice dead or dying leaves or vines, though, you can trim those away without a problem.
Hoya australis propagates well with cuttings rooted in either water or soil.
But it’s crucial to start with a good, viable cutting!
Take a cutting from a young, healthy section of vine that isn’t flowering. You’ll want to include several leaves and two or more nodes. It’s also best to do this in the spring or summer when your hoya is most likely to be actively growing. Take advantage of those growth hormones!
Next, you’ll want to set up your cutting in its home for the next few months.
Propagating in Soil
To propagate your Hoya australis cutting in soil, you’ll need to make a special, sterile potting mix from 3 parts perlite and 1 part coco coir or peat moss.
Then dip the cut end of the cutting in rooting hormone or use a little Propagation Promoter when you water to give your cutting a boost while protecting it from infection. Cover the top of the container with plastic wrap or a bag to keep the humidity in. Make sure to air it out once a day.
Placing the container on a heat mat can also encourage your cutting to take root!
Propagating in Water
To propagate your cutting in water, fill a clear glass container with rainwater, distilled water, or some other kind of dechlorinated water. Then dip the end of the cutting in rooting hormone or add a little Propagation Promoter to the water. Then place your cutting in the container with the end submerged, but don’t let the leaves touch the water.
Put it in a bright place and change out the water at least once a week, topping off in between as necessary. Within a month or two, you should have new baby roots! When those roots are at least an inch long, you can plant the cutting in soil and care for it like a grown-up hoya plant.
Size, Growth Rate, and Uses
Hoya australis is a moderate to fast grower, and can reach up to 30 feet outdoors if allowed to climb straight up. Indoors, vine can reach 9 feet long, though it can take upwards of 5 years to grow this large.
Uses for Hoya Australis
While Hoya australis has been traditionally been used for decorative and adornment purposes in cultures where it naturally grows, it also has valuable medicinal properties. The leaves can be made into topical remedies to treat skin conditions such as rashes, swelling, bruising, and even burns. It can also be taken internally as an infusion to treat stomach problems and inflammation.
Common Problems With Hoya Australis
Hoya australis is fairly hardy and not prone to many diseases, but it can be susceptible to household pests or develop root rot if overwatered.
Here are some problematic signs to watch for and what to do if you see them.
Pests like aphids, fungus gnats, spider mites, thrips, mealybugs, and scale can invade your Hoya australis. It’s a good idea to inspect your plant weekly and act as soon as you notice signs of an infestation, such as tiny red or brown dots, webbing, sticky clear residue (this is called honeydew), and, of course, actual insects. You might notice some of those tiny dots moving or see hard brown bumps on the leaves or stems (this is scale).
Try these tips for getting rid of various pests:
Thrips: These insects lay eggs in plant leaves, and then larvae feed on the leaves’ juices when they hatch. Use a lint roller on the leaves to remove as many insects as possible, and then spray the plant off with a kitchen sprayer. Tip the pot on its side to avoid washing more insects into the soil. Then spray your plant down with diluted neem oil. If that doesn’t work within a few days, use an insecticidal soap as well. You may need to do this a few times to combat several generations of thrips as the eggs hatch. If any leaves are severely affected, it’s best to simply remove them.
Spider mites and aphids: Rinse the leaves with a sprayer and use diluted neem oil to treat the leaves. Insecticidal soap can also help if you need to bring in the big guns. Introducing natural predators like ladybugs can also help, as long as you don’t mind having some friendly bugs around your home!
Mealybugs and scale: Pick as many of the scale off the plant as you can. You can also dip a cotton swab in rubbing alcohol and touch them to the scale to get them to release their hold. Neem oil or Leaf Armor Spray and insecticidal soap can help kill off stragglers and prevent further issues.
Fungus gnats: These lay their eggs in the top layer of soil, so use a spoon to scoop off the top few inches and replace with fresh soil. You can also sprinkle a little cinnamon on the surface to prevent them from returning.
Hoya australis doesn’t appreciate being overwatered and can quickly develop root rot if it sits in soaked soil for too long.
If you notice dark-brown spots on the leaves, especially if they’re accompanied by yellowing and/or mushy stems, you might have a root rot issue.
Repot your hoya into a clean pot with fresh, fast-draining soil. Make sure to get as much of the old soil out of the root ball as possible, and prune any mushy, dark, or stinky roots you notice.
Then put your plant back where it was, unless you determine that it needs more light. (Insufficient light can cause your plant to use water less efficiently, which can lead to root rot!) Let the soil dry out a little more between waterings, and use our Root Supplement when you do water to help the roots recover and protect them from further infection.
This can also be a sign of overwatering, but it may not indicate root rot just yet. If you don’t notice a bad smell coming from the soil and don’t see brown spots or squishy stems, just make sure your hoya is getting enough light and try letting your plant dry out a little more between waterings.
Make sure to check the moisture level of your soil to determine whether your plant actually needs to be watered rather than watering on a schedule. Your hoya’s watering needs can vary depending on the season, temperature, humidity levels, and whether or not your plant is actively growing.
Varieties of Hoya Australis
Hoya australis comes in several different varieties, each with its own distinctive coloring and leaf patterns.
The leaves of this subspecies are a bit larger than those of other Hoya australis varieties. They’re also a beautiful dark-green color. The flowers are similar to those of other Hoya australis subspecies’, but with slightly wavy petals.
This beautiful variety is prized for its fun, rounded leaves that start out small and thin and get larger and more rounded as they grow.
This variety grows beautiful flowers and has longer, narrower leaves than most other cultivars. It’s also slightly more drought-resistant than other Hoya australis varieties.
This lovely cultivar boasts striking lime-green and dark-green variegation, sometimes growing leaves that are perfectly half and half!
Also called Hoya australis tenuipes, this cultivar is known for its gorgeous variegation, with leaves with large patches of cream. These leaves may start off pink or red and turn white and green as they mature.
Hoya Australis FAQ
FAQ: Is Hoya australis toxic to pets?
Hoya australis is an excellent choice for pet owners because it’s non-toxic to humans and most domestic animals, as long as it’s not consumed in large quantities.
FAQ: How do I get my Hoya australis to bloom?
If your mature (5-7 years old) Hoya australis isn’t blooming during the late summer or early fall when it typically produces flowers, here are a few things you can try:
- Give your plant a dormant period by lowering temperatures to 10 degrees below what it’s used to for a month or so (but don’t let temps drop below 60 degrees Fahrenheit for long).
- Try switching to a phosphorus-rich fertilizer to support flower production.
- Make sure your hoya is getting at least 8 hours of bright, indirect light per day.
- Make sure humidity around your plant is at least 40%. You can do this with a humidity meter.
- Avoid moving your hoya around blooming season. If you recently relocated it, you may not get flowers this season.
- Make sure you aren’t overwatering. Let the top layer of soil dry out between waterings, but give the soil a good soaking when you do water.
FAQ: Why do the vines on my Hoya australis not have leaves?
Sometimes your Hoya australis will put out vines that don’t have any leaves on them. Why is this?
This could mean the plant is reaching for sunlight or something to climb. If your plant isn’t in the best lighting conditions, you might want to move it to a brighter spot. You could also give the plant a trellis or moss pole to climb.
You can also do nothing. Because this isn’t necessarily a sign of health problems, you could ignore it. The bare vine may sprout leaves once it finds what its looking for, or just randomly. You can also trim this vine off if it bothers you.
Final Thoughts on Hoya Australis
Overall, Hoya australis is an attractive and easygoing plant. Getting it to flower can be tricky if you don’t have the right conditions, but compared to other flowering plants, Hoya australis will flower pretty readily indoors.
This is a great intro to flowering plants and a gorgeous plant even without flowers, thanks to its beautiful, waxy foliage.
Try it as a hanging plant or a trailing tabletop or shelf plant. It will add a splash of color and fun shapes to any indoor space!
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