Hoya plants are beautiful, hardy, easy-to-grow houseplants known for their fragrant flowers. They come in a wide variety, from the beautiful heart-shaped leaves of the Hoya Kerrii to the fascinating Hoya carnosa 'Compacta' or 'Krinkle Kurl' (also known as Rope hoyas) and can be grown both indoors and outside. This delightful but often overlooked plant is commonly known as a Wax plant for it’s waxy leaves, and flowers that are so waxy they often don’t even look real! The best thing about a hoya plant is it will tolerate a certain level of neglect. You can often find them amongst the amazing collection of plants at your grandmothers'. My Grandma had a stunning one on her verandah for years!
Light requirements for Hoya plants
Hoya plants can survive in lower light levels, but they won't thrive or flower. To encourage flowering, hoya plants need plenty of bright, indirect light. However, too much direct light can burn the plant’s leaves, so it’s important to avoid exposing them to too much direct sunlight. If you live in a hot climate, you may need to protect your hoya from the afternoon sun. If it’s located in a north or northwest-facing window, a sheer curtain can help protect it from direct sunlight.
Watering tips for your Hoya
Hoya plants are generally pretty tough and can withstand less water better than more. They should be watered when the soil is dry to the touch. Overwatering can lead to root rot, yellowing leaves, and leaf loss. To avoid overwatering, it’s best to let the soil dry out completely before watering the plant again. When watering, it’s important to thoroughly soak the plant’s soil and let all excess water flow out of the pot’s holes. I usually water my hoya plants in our kitchen sink and leave them to drain well. Watering in the morning is best. I’m lucky I can water with rainwater at home, but another option is to fill an open container or jug with tap water a day before, and that will help any chlorine and fluorine gases dissipate; plus, your water will be at room temperature when you go to use it.
Always make sure you empty any water sitting in your plant’s saucer, as it can rob your plant of oxygen and encourage root rot.
Potting up your Hoya
Hoyas are epiphytes, which makes them similar to orchids. They like having their roots quite compressed as that mimics how the plant lives in the wild, so let your hoya be a bit root bound. Occasionally, over the years, you may find that it does need repotting, but much of the time, changing out the soil mix and using the same container is all it needs. Remaining rootbound can be stressful, but that stress can be enough in this situation to get it to bloom more. Only move up to a larger pot size if the pot is really rootbound and the plant looks much too large for the pot.
Hoyas prefer a well-draining, chunky soil mix with bark and perlite.
Hoyas should be fertilised during the spring and summer months. I find The Plant Runner’s Indoor Plant Food works a treat and encourages loads of flowers. It’s always best to fertilise straight after watering to avoid damaging the roots.
Pests and Diseases
Hoyas are relatively resistant to pests and diseases. However, they can be susceptible to mealybugs, aphids and scale. If you see any pests, you can treat them with insecticidal soap or neem oil. These pests can get out of hand, so consider quarantining any affected plants until the situation is under control.
Propagating your Hoya
Hoyas can be propagated from cuttings. Take a 100 – 150mm cutting from a healthy plant and remove the bottom leaves. Dip the cutting in rooting hormone powder and plant it in a well-draining potting mix. Keep the soil moist, and the cuttings should root in a few weeks. You can also leave the cutting in water to root. If you do this, it’s best not to leave it in water too long and make sure you plant it out into soil as soon as you see roots that are about 10 to 20mm long.
Hoyas can also be propagated from leaves, but this is a much more difficult method. I’ve only tried propagating from cuttings so far, and I’ve had reasonable success.
Encouraging your Hoya to Flower
If your hoya has never bloomed it could be for a number of reasons. Only mature hoya flower. Typically they need to be at least three years old and have stems that are at least a metre long. The other reason, if it’s a mature plant, is often because you’ve been spoiling it too much! It may just need a little more stress in it's life ...
A great tip for getting hoya plants to bloom is to withhold water for an extended period of time near the end of winter. In the winter, I normally water my hoya plants once every two weeks or so, depending on where they are in my home. To help force blooms in the spring, I add about another week to that. When the leaves begin to pucker and wrinkle a bit, I know it’s time for a good, deep drink.
If your hoya spends it's autumn and winter in air conditioned bliss or benefits from a wood fire, you can also try wintering your hoya by placing it somewhere that’s a little cooler over winter to encourage flowering in spring and summer.
A snug-fitting pot can also foster flowering. Ensure your hoya is getting sufficient nutrients, and fertilise it regularly in spring and summer.
If your hoya plant is over three years old and still not blooming, try moving it to a spot where it will get more hours of sunlight each day. Other signs that a hoya plant is not getting enough light include new leaves that are small and pale green, long sections of bare stem, slow growth, and dead mature leaves.
The most important thing with a hoya, once it has flowered, is to never cut off the flower spur left behind! This is where it will flower from again in future. It is safe to remove any spent flowers by hand. If you’ve already cut off any flower spurs, your hoya will grow more, but it will take time, as they’re not a fast-growing plant.
Some additional tips for caring for Hoya plants:
Hoyas can be pruned to encourage new growth and to maintain their shape. There is a common myth about not pruning them – but this only applies to the actual flower spur.
Hoyas aren't cold-hardy and should be brought indoors if the temperature drops below 10 degrees Celcius.
With a little care, a Hoya can be a gorgeous, fragrant easy-to-grow addition to any home and can thrive for many years.