Many houseplant enthusiasts are just discovering the joy of growing Hoya plants, also known as ‘wax plants’ or ‘porcelain flowers’. It is easy to be attracted to the Hoya’s lovely blooms, which vary in color across species and make a unique experience for everyone growing them.
Anytime we begin the incredible journey of growing new things, we encounter trials and errors. Although Hoya are one of the more forgiving houseplants, there is still a right and wrong way to care for them. In this article, I will hopefully provide helpful information that prevents those tragic errors.
Leaves are red on edges/leaves are burning: Your plant is getting too much sun or too much direct, hot light.
Note that some varieties will produce red or purplish leaves with new growth or immaturity; these are not sunburnt and you have no need to worry!
Solution: move your plant out of direct sunlight and back 2-4 feet or try moving your plant to another area of the home.
Plant becomes limp, wilted or there is dieback on growth: Overwatering or a lack of water.
The correct amount of watering is essential for the happiness of a Hoyas’ root system. Although Hoya are drought-tolerant, they still need water to be healthy. A good rule of thumb is testing the soil with a finger, if the soil is dry your Hoya needs water (this should be every couple weeks in the winter and every week or so in the summer). On the other hand, Hoya are very susceptible to root rot caused by overwatering. Root rot is the suffering of the roots being wet and soggy for a duration of time.
Solution: Check the roots, if there is a sign of root rot, take healthy cuttings of the plant immediately.** The signs of root rot can easily go unnoticed with Hoya because of the waxy nature of the leaves. It is not uncommon for all the roots to be unsalvageable by the time you notice something is wrong. In this case, it is just a matter of time before the rest of the plant suffers and it is best to rid of the entire thing (a plant lover’s, like myself, worst fear).
More Solutions: If the roots are not rotten, but your plant is unhappy, the solution could lie within several areas of care. Make sure the soil has good drainage by using an airy mix (repot with a perlite, potting soil, and orchid bark mix). After repotting watch your Hoya carefully; when transitioning from a dense soil to an airy soil, the plant might require more frequent watering.
Only water your Hoya when the soil is completely dry; water thoroughly then dump the excess water so the plant is not sitting in a wet saucer.
A tight pot can also help a Hoya’s root system because being root-bound can help prevent soggy roots and even encourage blooming. I don’t suggest repotting a Hoya that has been in the same pot for more than five years!
Internodes extended significantly: Could be lack of light and the plant is reaching for the sun.
Some varieties’ leaves are very sensitive (H. Meliflua) and will fall off with even the slightest touch so be aware that this could also be the issue.
Solution: Move your plant closer to a light source. Be patient & gentle.
Not flowering: Flowering is most affected by the happiness of the plant and the amount of light it is getting.
A Hoya that is not flowering might not be getting enough light. This also depends on the type of hoya and its origin of habitat. Some Hoya takes years to reach a maturity that allows inflorescence.
Solution: Needs more light, noting that most Hoya thrive with an excessive amount of direct light, or a stressor (being root bound or enduring a dry period). Read our journal article that talks specifically about getting your Hoya to bloom!
Buds fall off before blooming: Your potting medium is not correct.
The plant is too wet or too dry for a duration of time. A well-drainage potting system is key to growing a healthy Hoya.
Solution: Evaluate the potting medium that your Hoya is in and make adjustments accordingly. Your plant now needs nutrients from fertilizer or water to encourage more umbels. Make sure to correctly water your plant when you know it might bloom.
Leaves fall off abruptly: Cold draft or chill.
Your Hoya might be too cold in the wintertime. Hoya are originally a tropical plant that don’t love excess cold or heat. Leaf drop could also be a result of a poorly drained potting medium.
Solution: Keep hoya in a warm and humid environment. If indoors, place Hoya in a location that gets many hours of indirect sunlight. If outdoors, direct sunlight can prove to be too much for your Hoya; place it in bright shade to prevent leaf burn but still satisfy the need for lots of light. If nighttime temperatures fall below 50 degrees Fahrenheit, grow your plant indoors.
Sticky sap or mealybugs: sap-sucking insects (aphid or mealybugs).
Mealybugs, a sap-feeding insect that infests houseplants, can cause the leaves to shrivel up. The pests weaken the plant and excrete a sticky substance on foliage. Some varieties (H. kerrii, H. Imperalis, H. multiflora) naturally produce more nectar than others. This is natural. Aphids can appear on the flowers of the varieties that particularly produce lots of nectar, however, aphids are easy to rid of.
Solution for Aphids: You can use soapy water, neem oil, or essential oils to rid of Aphids. If outdoors, you can also introduce natural predators such as ladybugs, green lacewings, and birds.
Solution for mealybugs: Clean the sticky sap off the leaves, the sap invites more pests and mold so you want to take care of it as soon as possible.
Non-pesticide prevention: Mealybugs are not airborne so isolate your plant for at least a month to ensure that they won’t infest your other plants.
Remove dead leaves and pruning that could be infected with the bug
Use sharp sprays of water to knock off the bugs
Sometimes the plant is too sick to salvage and it is simpler to take some healthy clippings and restart or to rid of the plant entirely.
Pesticide prevention: Recommend horticultural oil or neem spray to rid of mealybugs. Neem oil is a naturally occurring pesticide that is found in the seeds of the neem tree. It works beautifully to grow healthy Hoya.
The best way to keep your Hoya happy is by getting to know it. Not all Hoya were made equally! Most Hoya require hot and humid environments because they hail from tropical and subtropical regions, however, higher altitude species do exist and can endure colder climates. Some Hoya prefer having dry periods and others like being thoroughly watered. Research the variety you own and learn about its needs! Vermont Hoyas is a personal favorite resource to help identify Hoya.
When you invest the time in learning how to communicate with your plant, you’ll be amazed at how much they communicate to you. Being connected through their growth is the number one way to grow a healthy, happy plant.
**How to identify root rot: roots are gray to black and can also be mushy or dry.**