Hoya Nummularioides is a rare houseplant with small leaves and fragrant flowers that grow in clusters. Fortunately, they are beginner-friendly plants. Just follow these tips for your plant to thrive:
- Place your plant in a warm and humid location (>60% humidity) with more than 6 hours of bright but filtered light. East or West-facing windows are ideal.
- To encourage blooms, ensure your plant has enough indirect light and use a liquid fertilizer monthly during the growing season at half-strength; you’ll love the sweet, jasmine scent of these strongly scented blooms.
- Use a well-draining and airy potting mix.
- Avoid overwatering; water only when the topsoil is dry.
- Prune lightly but don’t deadhead flowers or trim off old peduncles as this is where new flowers grow.
Let’s dive into the details!
Table of Contents
What is the Hoya Nummularioides?
Hoya Nummularioides is a rare houseplant prized for its succulent-like leaves and clusters of white flowers.
Flowers form flat clusters (rather than ball-shaped clusters like some other types of Hoyas) and give off a jasmine or honey scent. 🙂
Its foliage is small, round, and plump.. with a layer of fuzz!
Caring for your Hoya Nummularioides
Like many rainforest epiphytes, your Hoya Nummularioides loves plenty of bright but filtered light.
Bright light encourages healthy foliage and flower growth, but be careful not to place your plant in the path of direct sunlight during afternoons when the sun is at its hottest. This is because its leaves are used to receiving sunlight filtered through a canopy of trees. So, harsh direct light is simply too intense for your plant.
Placing your Hoya Nummularioides in a West or East-facing windowsill is ideal. Here it gets enough indirect light (>6 hours a day) that is not too intense.
Placing near a South-facing window can work, too; just ensure your plant is about 3 feet away (0.9metres) from the window to lessen the light intensity. Alternatively, you can use a shade cloth to filter the sunlight it receives.
Because your plant has semi-succulent leaves, it has lower water requirements than a typical houseplant. These thick leaves allow your plant to store water, reducing the need for frequent watering.
At the same time, as with many epiphytes, they have specialized root and leaf systems that maximize water absorption and reduce water losses through transpiration. When kept as a houseplant, they are more susceptible to being overwatered than underwatered.
You can tell your Hoya Nummularioides needs watering when its top 2 inches of soil is dry. Always check using your fingers before deciding to water your plant. If you notice any dry or brittle leaves, this also signifies that your plant needs water.
To prevent overwatering, be sure to choose a planter with drainage holes, and empty its saucer after watering. In addition, choose a well-draining potting mix: we’ll show you how in the Soil section below.
If you accidentally overwater your Hoya Nummularioides, bring your plant outside to a shady spot to air dry. Let the plant dry outdoors for a few days. Only water again after you check that the soil is completely dry again.
In more severe cases of overwatering, you may need to check for root rot. Check out our guide on how to save your overwatered plant.
While thick leaves provide some immunity against low humidity levels, if you want to encourage your Hoya Nummularioides to bloom and grow more quickly, you need at least 60% humidity.
A 60-75% range is ideal (the more humidity, the better!). These levels are usually higher than normal room humidities, depending on where you live.
You will notice a slower growth rate at levels lower than 60%.
We don’t recommend misting your Hoya Nummularioides, as wet leaves encourage the growth of bacteria and fungi. Furthermore, the effects of misting are short-lived.
Hailing from the tropical southeast Asian countries of Thailand and Cambodia, your plant prefers warm temperatures year-round. Ideally, your plant loves to be in environments between 65-90 degrees F (18 – 32 degrees C), with the higher end of this range being ideal.
Dips in temperature below 60 degrees F (16 degrees C) will cause your plant’s growth to slow. Like most houseplants, your Hoya prefers stable temperatures, so keep it away from air vents or drafts.
Growth and Flowering
The Hoya Nummularioides has small leaves and flowers. In fact, it has one of the smallest flowers of all the Hoya genus (over 500 species!). A cluster of flowers may be smaller than 2 inches (5 cm)!
Though small, these flowers have a strong and lovely jasmine or honey-like fragrance. They are known to be one of the most strongly-scented blooms in the genus.
Flowers typically bloom in the spring and fall and grow in a few different colors, depending on the specific Hoya Nummularioide type. The more common Hoya Nummularioide types are:
- Hoya Nummularioides Constantin
- Hoya Nummularioides Red, Pink or Yellow
However, the most common Hoya Nummulariorides flowers are white and star-shaped with a pink-red corona.
To support your plant’s long vines, you can either let it climb up a trellis or moss pole or allow it to cascade from a high-hanging basket (our personal favorite).
Another plus point is that your Hoya Nummulariorides enjoys a rapid growth rate. It may grow up to 7 feet (2.1metres) long when grown indoors, though this will take several years. Our experience has been that you can see a couple of vines grow in about two months.
Being the impatient people that we are, we like this characteristic!
The Hoya Nummularioides may go into dormancy during winter once it senses drops in temperature and lower levels of sunlight. During this time, your plant conserves its energy and continues to carry out basic chemical and metabolic processes. However, it does not actively put out new growth during this time, as it senses that growing conditions are not optimal.
It’s a smart thing to do on your plant’s part to conserve energy. Don’t worry, this is natural and nothing to be worried about.
However, there are a few things you need to do to ensure your plant is not overwhelmed during dormancy:
- During this time, hold off on fertilizing. Too much fertilizer when your plant is not actively growing can damage your plant’s roots.
- As always, allow your plant’s soil moisture to dictate when it needs watering. You’d find that your Hoya Nummularioides’s water requirements reduce significantly during this period, as it is growing less.
Soil or Growing Medium
When thinking about the best potting mix for your Hoya Nummularioides, there are a couple of things to keep in mind:
- Being an epiphyte in nature, your plant can grow in small bits of organic debris and moss. It’s cool like that!
- Your plant has aerial roots, which means roots grow above-ground, allowing maximum breathability.
- The Hoya Nummularioides is susceptible to overwatering. It hates stagnant water pooling at its roots.
Taken altogether, the best potting mix for your plant is one that is airy, well-draining, and also provides some organic nutrients.
The best soil mix for your plant is a mixture of:
Such a mix best mimics your plant’s native environment and gives it nutrients to support healthy growth.
While your plant is a light feeder, to encourage blooming, it benefits from a nutritional boost! We like to use Dyna-Gro Grow and fertilize monthly at half-strength during the spring and summer months. We find that it makes a HUGE difference in flowering and the plant’s overall health.
Hold off using fertilizer in the fall and winter months. Your plant doesn’t need it, and fertilizing it during this time may cause fertilizer burn, damaging the roots.
While your plant is a rapid grower, it has a small root system, so it needs repotting less frequently than you might guess! As a rule of thumb, expect to repot your Hoya Nummularioides every 2-5 years.
You will know that it’s time to repot when your plant’s roots start to peek out from the drainage hole. During this time, you may also notice slowed growth and a sense that your plant is thirsty like it is not satisfied no matter how much you water it! All this means insufficient soil and space for the Hoya Nummularioides’s rootball.
When repotting, be gentle with your plant, using your fingers to work through compacted soil. Don’t yank at the stems, which will likely break and damage your plant’s roots.
Be sure to use a pot just 2-3 inches larger than the original pot. Also, use new soil when repotting, as nutrients in the potting soil will deplete over time.
Like all Hoyas, your Hoya Nummularioides is not considered toxic to humans or pets. However, be careful of the milky sap that comes from cut stems – this may cause skin irritation. It’s good to use gardening gloves when pruning or propagating your plant.
Pruning is a part of plant maintenance. Here’s some tips for your Hoya Nummularioides:
- Do not deadhead flowers or cut off flower peduncles (from which your flowers emerge). This is because new flowers re-use the same old peduncles!
- Being a rapidly-growing vining plant, it can get unwieldy. Prune to give a bushy shape to your plant and keep it compact.
- Remove any yellowed, wilted, damaged, dead leaves, and leggy stems. This allows your plant to focus its energy on new growth.
Stem cutting is an easy way to propagate your Hoya Nummularioides.
- Identify a healthy stem portion about 4 – 6 inches long. Make sure that this length of stem has a few leaves and at least two nodes!
- Using clean garden shears, snip off the identified stem just below the node (the knobby part of the stem, from which new growth will emerge!).
- Remove any leaves from the bottom half of the stem cutting.
- Place the stem cutting in a jar filled with room-temperature water. Ensure no leaves are submerged, and at least one node is underwater. Roots will grow from the nodes in time!
- Place the water jar in a warm spot with indirect light. If you can, place a humidifier next to the water jar.
- Change out the water every few days with fresh, room-temperature water.
- In about a month, you should see roots growing.
- When the roots are about 2 inches long, remove the stem cutting from the jar. Repot in airy and well-draining potting soil (see Soil section for details)
- Treat as you would any other Hoya Nummularioides.
Common Pest and Diseases
Since overwatering is one of the most common issues for Hoya Nummularioides, it’s no surprise that root rot is a common disease.
Root rot is the result of an overwatered plant. It happens when water crowds out air molecules, preventing your plant’s roots from breathing. This suffocation causes root damage and decay.
Separately, root rot can also be caused by moisture-loving fungi feeding on overwatered roots.
In both cases, the result is soft and mushy black or brown roots. They sometimes have a foul smell and are unable to perform the normal function of the roots: drawing water and nutrients to the plant.
In severe cases, root rot leads to plant death. Here’s our guide on how to save your overwatered plant from potential death via root rot.
Mealybugs are a common houseplant pest. Unfortunately, they especially like your plant’s succulent-like leaves and its sweet sap. Your plant is sweet-smelling and, when blooming, may have excess nectar dripping from its flowers.
These bugs cluster together on hard-to-reach corners of your plant, like leaf axils. They work by feeding on your plant’s sap, thereby depriving your plant of nutrition. By doing so, they also damage tissue cells.
Lastly, mealybugs have an unfortunate quality of secreting honeydew as they feed on the plant sap. This honeydew attracts sooty mold and fungi to breed on your plant.
These pests are problematic, but your plant can be saved if you act quickly. Here are the ways you can identify and get rid of mealybugs.
How do I know if my plant is nutrient-deficient?
Pale leaves and stunted growth usually point to nutrient-deficient Hoya Nummularioides. Other signs include a lack of flowers, small leaves, and brittle and weak vines.
We recommend using a liquid fertilizer once a month during the growing season to give your plant a nutritional boost. Also, ensure that your plant has potting soil rich in organic nutrients; see the Soil section for our recommendation!
How do I encourage blooming?
Here are a couple of things to keep in mind:
- Flowering requires lots of bright indirect light. At least 6 hours a day is necessary for blooming. If you struggle to find enough natural light for your plant, use a grow light.
- High humidity of at least 60% encourages blooming. Use a humidifier if you live in an arid region.
- Allow your plant to get slightly root-bound. This promotes flowering.
- Remember not to trim off old peduncles, as this will be re-used by new flowers!
- Lastly, be patient and enjoy the process! Flowering takes time.
Frequently Asked Questions
Where can I buy a Hoya Nummularioides?
Try private sellers on Etsy. Being a rare plant, you can expect to pay a bit of a premium for this Hoya, but on average, this should be around US$40-60 depending on the size.
Where does my Hoya Nummularioides come from?
Many Hoyas originate from Asia. The Hoya Nummularioides, in particular, originates from the tropical rainforests of Cambodia and Thailand and other parts of southeast Asia. They grow as epiphytes, on top of host trees and other plants, and receive sunlight through a canopy of trees.
What kind of scent does the Hoya Nummularioides have?
The Hoya Nummularioides has a sweet, jasmine-like scent. Other descriptions include a floral and honey perfume-like fragrance.
Similar Plants and Varieties
As mentioned, the Hoya Nummularioides may come in a few different forms. Different forms have different colored flowers.
- Hoya Nummularioides Constantin
- Hoya Nummularioides Red, Pink or Yellow
Other Hoyas we love include:
- Hoya Macrophylla
- Hoya Krimson Queen
- Hoya Krimson Princess
- Hoya Carnosa Compacta, the Hindu Rope Plant
- Hoya Linearis
- Hoya Curtisii
- Hoya Obovata
- Hoya Pubicalyx
- Hoya Kerrii, the Sweetheart Hoya
- Hoya Bella
- Hoya Imbricata
- Hoya Serpens
Deborah is a plant enthusiast and founder of Gardening Collective.