Hoya Merrillii is a native plant from the Philippines and is one of the most stunning plants from the Hoya genus. This plant belongs to the Apocynaceae family and from the subfamily known as Asclepiadoideae.
This plant is epiphytic, meaning it needs the support of other plants to grow upwards. However, you can grow your plant hanging in pots, or if you want it to grow upwards, then you can provide it with some form of a support pole.
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Basic Plant Care for Hoya Merrillii
Hoya Merrillii is one of the easiest plants to grow since they require less maintenance as compared to other plants. This plant needs to be kept in well-draining soil, which can be made through a mixture of Orchid bark, Potting mix, Horticultural charcoal, and perlite. For lighting, situate it in bright, filtered sun.
Soil
Hoya Merrillii is not picky about the type of potting mix it prefers. As long as your plant has been provided with proper draining soil, it will grow well.
You can use any form of indoor potting mix or find a soil mix with a mixture of chunky and porous materials, as it helps with your plant’s growth by preventing excess water from staying within the soil.
This plant is susceptible to rotting of the roots if it is overwatered or if the plant has not been kept in well-draining soil. You can also use the following soil mixture for your Hoya Merrillii:
- Orchid bark
- Potting mix
- Horticultural charcoal
- Perlite
The soil mixture is not the only thing that you must take care of. Your plant must be kept in soil that meets its pH levels. Hoya Merrillii survives best in soil that has a pH of 6.1-6.5 (which is slightly acidic) to 6.6-7.5 (which is neutral).
This plant’s USDA hardiness zone is 11a to 11b.
Watering
Hoya Merrillii needs an average amount of water to survive. The plant should never be watered too often as it can lead to over-watering of your plant. You should let the soil dry up before you water it again so that you have a good idea of when you should water your plant.
I personally water my plant only after the soil has dried up while letting it stay dry for a few days.
When the winter season arrives, you need to keep the plant dry and give it plenty of sunlight.
If you do not keep the plant dry in winters, then there is a high chance that the plant will get some fungal infections.
But once the winter season has come to an end, you need to start rewatering your plant more often and provide it with higher humidity levels.
During the summer season, Hoya Merrillii requires a lot more water as high heat evaporates the water faster.
Keeping your moist soil the majority of the days during summer won’t cause your roots to rot.
During the spring season, you can let the plant rest outside for a while so that it can soak up some rainwater and sunlight for growth.
The flowers on Hoya Merrillii bloom during the spring and summer season, so providing them with direct sunlight for a small amount of time is essential.
Light
Hoya Merrillii likes to be kept under indirect sunlight. The plant can tolerate direct sunlight for a short period of time, but keeping it under direct sunlight will cause some burns to your plant, leading to yellowing of the leaves.
Temperature
The temperature of Hoya Merrillii should be kept between the range of 40 degrees Fahrenheit (4.4 degree Celsius) to 50 degrees Fahrenheit (10 degree Celsius).
Hoya Merrillii can tolerate outdoor temperatures, but it is best to keep them under room temperature to ensure that they live a long life.
Humidity
There are several species of Hoya, and all of them have their own preference for humidity levels. However, when it comes to Hoya Merrillii, they prefer to be kept in humidity levels that are around 60%.
The plant can survive well in household humidity levels as well, but it won’t grow as fast
.
Fertilizer
Hoya Merrillii is an epiphytic plant and can take up nutrients through their foliage; this means that the plant is capable of taking in nutrients while it climbs up a supporting plant.
However, even the Hoya Merrillii enjoys being fertilized occasionally to promote growth, especially during the spring and summer seasons since the plant is in its growing stage then.
To fertilize your Hoya Merrillii, use an organic fertilizer that has a balanced ratio of phosphorus and nitrogen in it. You can fertilize our plant on a weekly to monthly basis.
Keeping a schedule for your fertilization sessions is a good idea as this will prevent you from over-fertilizing your plant.
You can also use synthetic fertilizer at a quarter of its strength.
I like to spray my Hoya Merrillii once a month.
Many people prefer spraying their Hoya Merrillii at least once every week, but keep a larger gap between your sprays to ensure that you won’t end up over-fertilizing your plant and cause the leaves to turn yellow.
Repotting
Hoya Merrillii can remain in its first pot for up to three years.
This plant does not like getting repotted too often as it loves being pot bound. It is recommended that you repot your Hoya Merrillii only when it is absolutely necessary.
Hoya Merrillii has a greater chance of getting damaged due to the stress you may cause while trying to repot the plant.
The blooms of this plant appear when the plant stays root-bound for a long period of time.
The best thing to do for your Hoya Merrillii is to let it stay within its nursery pot.
If the appearance of the pot does not suit your taste, then it is best to pick a pot that matches your aesthetic at the beginning stages of potting the plant.
I like to repot my Hoya Merrillii when:
- The potting mix that my Hoya Merrillii is placed in starts to hold in too much water. Overly moist soil can cause your roots to rot.
- The plant is starting to show signs of some form of infection or invasion by pests.
- The soil starts to get dry easily, even when the plant is being watered regularly.
- I must observe the roots of my plant to check its health and condition.
- My plant is a lot smaller in size as compared to the pot, even after I have grown it for months or years.
Pruning
When you prune your plant, you have to be really careful with it as it is extremely sensitive to rough handling.
Do not try to chop off any areas of your plant that may have spurs on it. The spurs on your plant are responsible for growing the stunning flowers.
Even when the flowers from an old spur start to fall off, they will grow back once the growing season arrives again.
By every passing year, the quantity and quality of flowers that bloom from old spurs increases.
If you have to cut off a part of your plant even when it has spurs on it, then it is okay since the plant will not die if you cut off its spurs.
Old spurs are always a preference in the gardening community since they produce more blooms.
To prune your plant, follow these steps:
- Grab a part of your plant that you would like to cut.
- Look for a good angel to cut your plant off of since bad angels will cause damage to your whole plant.
- Remember to use sharp equipment when pruning your plant. To sanitize your equipment, use rubbing alcohol on it.
- Always cut your plant just below the nodes so that you do not cause excessive damage to it.
- Chop all unhealthy leaves or infected areas of your plant.
Propagation
Hoya Merrillii can be propagated in several ways. However, before you decide to propagate your plant through these methods, there are some procedures you must do in order to propagate your plant. These include:
- Cut off every part of your plant that is infected with a disease or has spots on it.
- Pick a part of the plant that seems suitable for replanting. You should pick a vine in your plant that is not growing or has some immature leaves on it.
- Find the node of your Hoya Merrillii, and from the node area, cut off the plant from the last node of the leaf.
- Always use sterilized equipment for your propagation, as this reduces the chances of causing infections to your plant.
- For the last step, you may dip the cut part of the stem into a rooting hormone, as this helps with your plant’s growth. However, this step is not necessary.
Once you have followed all of the above steps, you can start to propagate your plant from the following methods:
- Water propagation: Propagating your plant in water is one of the easiest ways to do it. Hoya Merrillii easily propagates in water; all you must do is place the plant cutting into the water and change the water once it becomes cloudy.
It is recommended that you change your water regularly even before the water starts to get murky. If you forget to change the water regularly, this will cause the water to stagnate. Stagnate water causes bacterial activities to increase, and this will cause your plant to die due to lack of oxygen.
- Perlite propagation: Even though propagating your Hoya Merrillii in water is easier, it is still recommended that you propagate your stem cuttings in perlite.
The reason why perlite is preferred is because of the fact that it allows air to flow around the cutting of the stem, which reduces the chances of root rotting. To propagate your plant in perlite, just follow these steps:
- Find a container that can hold your cutting in it. Any container is fine in this step. You can use food containers or even plastic bottles.
- Add perlite to your chosen container to about an inch in the container.
- Add water to the perlite and let the perlite soak in the water for a few minutes
- Drain the excess water out of the perlite until your perlite becomes damp.
- Place your stem cutting into the perlite container
- Bury the stem into the perlite, but make sure to leave some uncovered leaves at the top.
- Cover your container with a plastic wrap or anything that will not allow air to pass through quickly so that you can increase the humidity levels.
- Place the container in a warm and bright area, but not keep it under direct sunlight.
Blooms
The blooms of Hoya Merrillii are whitish-yellow in color. Even the center of the plant is a slightly darker yellow as compared to the flower’s petals. The flowers of Hoya Merrillii only bloom when they are provided with direct sunlight for a short period of time.
Growth
If your Hoya Merrillii is provided with optimum growing conditions, then your plant can grow to a length of 6 to 8 ft. This plant grows the most during the spring and summer seasons.
The leaves of Hoya Merrillii are also stunning in appearance since they are dark green in color and have tints of maroon in them, especially at the leaf’s edges. The plant’s leaves are glossy, and they have visible veins on them, which makes this plant easy to propagate.
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Common Problems for Hoya Merrillii
Aphids
Aphids are a common occurrence in almost every Hoya plant. Hoya Merrillii is no exception to it either, as these pests often attack it for its nutrients.
When aphids suck out the nutrients from the plant, they leave behind a sticky honeydew that attracts fungal diseases and ants to the plant, causing it a lot of damage.
However, getting rid of aphids is easy since all you have to do is cut off the infested part of your plant, or you can rub some neem oil on to leaves to prevent further infestation.
Mealybugs
Hoya Merrillii are easy targets for mealybugs since they can hide under the large leaves of this plant. They have a white appearance, which makes it hard to spot on the plant’s leaves.
Mealybugs also tend to leave behind a sticky residue, causing fungal infections to your plant, causing them to turn yellow and curl up.
Mealybugs are easy to control if they are caught during their early stages of infestation. To get rid of them from an infected plant, all you have to do is rub some alcohol on the plant’s leaves.
If the infestation still proceeds to increase, then using pesticidal sprays is a good idea as well.
Scale
Scales are extremely hard to get rid of once your plant has been infested with them.
These pests have a scale-like armor on them that makes it hard for pesticide sprays to kill them.
The easiest way to remove any scales from your plant is by handpicking them or spraying pesticide spray one day and observing for a little while to remove any scale that did not die due to the pesticide spray.
Spider mites
Hoya Merrillii thrive in humid climates; this makes them ideal spots for the growth of spider mites. Spider mites tend to invade plants that live in high humidity areas and where the weather is warm.
You can get rid of them by spraying your plant with high-pressure water on the leaf’s front and backside. Make sure to blast water on the stems of the leaves as well. For further precautions spraying your plant with pesticidal spray once a week is also a good idea.
Tips for Growing Hoya Merrillii
Hoya Merrillii requires very little care and can grow well if the following tips are followed:
- Keep your Hoya Merrillii in humidity levels of up to 60%.
- Water your Hoya Merrillii once the soil has dried up from the top.
- Keep your Hoya Merrillii under indirect sunlight and occasionally provide it with direct sunlight for a few hours.
- Fertilize your Hoya Merrillii at least once a month during its growing season.
Frequently Asked Questions about Hoya Merrillii
Should I mist my Hoya Merrillii?
Misting your Hoya Merrillii will help increase the humidity levels if they are low. Make sure that when you mist your plant, you do not overdo it.
How often should I let my Hoya Merrillii sit in the sun?
Keep your Hoya Merrillii in the sun for at least 2 hours in the day.
What fertilizer is good for Hoya Merrillii?
Slow releasing fertilizers are the best choice for Hoya Merrillii.
What time of the year will my Hoya Merrillii bloom?
Hoya Merrillii bloom in the spring and summer seasons.
Is my Hoya Merrillii not safe for cats?
Hoya Merrillii is toxic for all animals and humans; thus, it should not be ingested.
Conclusion
Hoya Merrillii has some of the most adorable blooms in the Hoya genus. This plant looks stunning in every garden setting and can bring a spark to your collection of plants. They require very little attention; thus, if you forget to water them for a few days, you won’t have to worry about it dying.
Daniel has been a plant enthusiast for over 20 years. He owns hundreds of houseplants and prepares for the chili growing seasons yearly with great anticipation. His favorite plants are plant species in the Araceae family, such as Monstera, Philodendron, and Anthurium. He also loves gardening and is growing hot peppers, tomatoes, and many more vegetables.