How to Grow and Care for Hoya Plants
Once you bring home a Hoya houseplant, one thing is certain: you will want more! Fortunately, with hundreds of different species, these adorable plants with enchanting blooms are easier to care for than expected. In the right environment, these plants will thrive in your home, even with minimal care and attention.
This guide will help you set your Hoya plant up for success and encourage plenty of new growth, even if this is your first-ever houseplant. We'll discuss everything your Hoya needs to flourish, from soil mix to light requirements, humidity and temperature, pet safety, and how to water your Hoyas.
The Natural History of Hoyas
Hoya is a genus of plant with over 500 recorded species, and more are constantly being discovered or cultivated. While they attract the eyes of houseplant lovers worldwide, Hoyas also grow natively in several countries in Asia, and some species can be found in Australia. Many hoyas are epiphytes, meaning they grow on other plant life, such as trees, with the help of their long tendrils and adventitious roots. As houseplants, this makes them easy to train to grow up a trellis, or if you prefer, they will happily grow as trailing plants.
Botanist Robert Brown named the Hoya genus in the early 1800s, naming it after his close friend and fellow botanist Thomas Hoy. While hoyas tend to have succulent-like characteristics, they are part of the milkweed family, Asclepiadaceae. This is due to the milky white sap within their stems and unique blooms forming in a cluster. Hoya species range from having thick, plump leaves and woody stems to those with thinner, more waxy leaves, earning them the nickname 'wax plant.'
Light Needs for Hoyas
Hoyas will tolerate medium light, but most prefer bright indirect light. They do spectacularly in an Eastern window, getting plenty of indirect morning sunlight. They can even tolerate 3-4 hours of direct light, if it is gentler morning sunlight. Too much afternoon light or direct sunlight can cause dark, crater-like scabs on their leaves. Hoyas also do well under artificial grow lights if you want to encourage growth and suspect you don't have enough natural light. When given ample light, Hoyas may start to develop a purple hue in their leaves due to the hormone anthocyanin. Though sometimes called sun stress, this doesn't have harmful effects and can result in beautiful contrast in the foliage.
Watering Hoyas
Generally, you want to water your hoyas when the soil is nearly dry but not completely dry. However, the type of hoya species you have can influence how often you should water them. For example, if your Hoya is a more succulent-like variety, such as a Hoya Carnosa, Hoya Rope Plant, or Hoya Chelsea, you can allow the soil to dry out completely. Their thick leaves are capable of storing additional water reserves. When thirsty, their leaves will pucker, wrinkle, or become soft to the touch.
On the other hand, if you have a more delicate species of Hoya, such as Hoya Curtisii or Hoya 'Grass Leafed,' you will want to wait until the soil is nearly dry but not completely dry. Their leaves are slightly thinner and, therefore, cannot store as much water.
Soil Requirements for Hoyas
Since hoyas are epiphytes in the wild, they do not like the thick, densely packed potting soil mix you traditionally buy at a store. This type of soil won’t have enough drainage and can lead to root rot. Otherwise, hoyas are versatile and can do well in sphagnum moss or a semi-hydro environment like Leca. If you are going to pot your Hoya in soil, the best choice is a light, airy mix such as James's Ultimate Potting Mix for Succulents. This mixture has plenty of coco coir, perlite, and rice hulls to keep the soil airy and will help mimic their native habitat.
Temperatures and Humidity for Hoyas
Given the areas where Hoyas grow naturally, you want to ensure that your plant receives warm temperatures, between 65°F (18°C) and 85°F (29°C). Keeping temperatures on the cooler side can slow down blooming so ideally, you want to keep your Hoya in an environment above 68°F (22°C).
In general, Hoyas prefer humidity levels between 40-60%. Hoyas that are thicker and succulent, such as the Hoya Carnosa, can tolerate those lower humidity levels, whereas the slightly more delicate species, such as the Hoya Curtisii, would appreciate humidity levels closer to 60%. One thing to be careful of when giving your Hoyas humidity is to avoid water pooling on the leaves, which can cause them to develop fungal infections or even a bit of leaf rot.
Fertilizing Hoyas
Hoyas typically enjoy being a bit root-bound, so they often don't require frequent repotting. However, this means you may find that your Hoya’s soil will gradually lose nutrition if you don't fertilize it. Hoyas benefit from a balanced, water-soluble fertilizer once per month during the growing season. Since many people keep Hoya houseplants hoping to get those beautiful blooms, you can even choose a fertilizer that contains more Phosphorus, which encourages the development of flowers.
Pet Safety and Hoyas
While it is generally accepted that hoyas are non-toxic houseplants, there is plenty of debate about whether the sap from the stems can be toxic or cause an upset stomach. While there is likely no need to panic if your pet has nibbled on a hoya leaf, the sap in the Hoya stems can also be an irritant for pets. Fertilizers, pest treatments, and soil material can also be toxic for our pets. It's best to keep hoyas out of reach from your pets and contact your veterinarian if you notice your pet experiencing any adverse effects if they come in contact with the plant.
Conclusion
Here are a few important points to remember if you're ready to grow happy and healthy Hoya houseplants in your space:
Lighting: Give your Hoyas bright, indirect light if you want to see plenty of new growth.
Watering: If your Hoya has thicker leaves, you can allow the soil to completely dry out between watering. Otherwise, keep the soil moist but not wet.
Soil: To prevent root rot, give your Hoya plant a chunky soil mix, such as James's Ultimate Potting Mix for Succulents.
Temperature and humidity: Hoyas enjoy warm temperatures above 65°F (18°C) and humidity levels between 40% and 60%.
Fertilizing: Use either a balanced, water-soluble fertilizer or one that favors Phosphorus to encourage blooms.
Pet safety: While Hoyas are considered safe for pets, it's best to keep them out of reach as they produce a white sap in the stems, which can be an irritant if chewed.
These tips will help you through what will likely be just the beginning of your joyful Hoya houseplant journey.
If you have any more questions about caring for your Hoya plants, consider joining my Plant Club community and reaching out.
Happy growing!