If there is one group of plants that are enjoying the limelight it’s Hoyas. Hoyas have exploded in popularity in 2020 + there are lots of varieties entering the houseplant market right now. In this post, I’ll be sharing how I look after my hoya gang as I’ve been getting quite a few questions over on my instagram.
But before we get into that, it is crucial at this point to emphasise the importance of obtaining your plants from a reputable source. I have readers from all around the world + issues surrounding plant conservation, poaching + endangered species being sold online for huge sums of money is a very real problem. Purchasing plants through responsible methods makes sure you are able to trace where the plant has come from + ensures it has come into your possession via legitimate means.
I currently have three hoyas in my collection; a hoya carnosa tricolour, linearis + pubicalyx. As I said in my previous post, they are certainly a plant I have been enjoying growing this year + after keeping my three hoyas alive + well for a decent amount of time, I will share how I care for them here. When I’m getting to know a new type of plant, I make sure to take time to learn about it; researching online, reading my plant books + studying the new growth closely. Taking regular photos can also be a good way of familiarising yourself with little details too, such as growth habits + leaf development.
Hoyas do like a decent amount of light; so a position with bright but indirect light will keep them happy. For my hoya family, I keep my linearis hung in the corner of my living space — pretty much next to the south-east facing window where I have put up a net to diffuse the light. I don’t have curtains so my plants can get maximum light early in the morning as the sun rises as this cottage I’m staying in temporarily is pretty dark.
Variegated hoyas like my carnosa tricolour need more light than non-variegated types but make sure the intensity isn’t too much for the waxy leaves which can cause them to scorch. My carnosa tricolour is a bit closer to the net than my linearis + is positioned on a table, so it is close enough to the window to get good levels of light throughout the day. The most forgiving of my hoya trio is my pubicalyx which lives in my bedroom. It’s still a south-east position but the light is not as intense as downstairs because of the way the cottage faces. It’s around a metre away from the window on my dressing table + has been growing well for me this season. Prior to moving, all these plants were in my south-west facing bedroom which also worked well for them. Bear in mind that these are the conditions that are personal to my current environment + are used as a guide for you to compare with your own home. As I touched on above, it’s important to also remember that windows can be pretty different in size + if you live in a built up area, with other buildings close by, or if there are obstacles like trees outside, this all has an impact on the intensity of light.
If you are hanging your hoyas, be sure not to hang them too high which might result in the top of the plant not getting enough light. I tweaked the length of my plant hanger to make sure it gets good light on top too. Something I’ve learned to be aware of over the years of keeping more mature hanging plants here at HPH is to asses the whole area they cover — make sure all parts of the plant are getting light so that they can continue to grow healthily. A potential issue is that parts that aren’t getting enough light will die back which can create an imbalance in how the plant looks. If your plant outgrows the space, consider hanging it differently or pruning it (more on that later).
Hoya plants appreciate moderate to high levels of humidity to really thrive so a well-lit bathroom would be an ideal position for them. When I move next, I plan to have a hoya shelf in the bathroom if it is bright enough! Just make sure they aren’t left too close to open windows with potentially cold draughts. The fuzzy-leaved linearis requires more humidity than the thicker, waxy-leaves of the carnosa + other similar varieties.
For me, a combination of keeping a lot of plants + living in an old property means the humidity readings here at HPH are regularly around 60-70% without a humidifier. If you do use a humidifier with your plants, the hoyas in particular will like it. Just be aware that with increased humidity, you might be able to go longer between waterings.
I give all my hoyas a shower around once a month to ensure the leaves are kept free from dust + looking their best…the glossy, waxy foliage looks great just after a clean! After showering, I leave the plants to drip-dry in the shower for 30mins, then shake off any excess water + put in a warm position out of direct light to dry. I wouldn’t recommend showering your plants at night, wait until the morning so that they can dry off properly before the temperatures drop.
In terms of watering, too much is a no-no. During the growing season, water when the top layer of potting mix has dried out (sticking your finger in to check is the best way!). Don’t keep the plant extremely wet, or you will be likely to get problems with rot. Over winter, I reduce watering to around once a month. If you have the nursery pot within a cache pot, always remove it before watering. I tend to water my long hoya in the bath, draping the plant over one side + always use tepid (room-temperature) water so as not to shock the roots. As you might imagine, the thinner-leaved varieties that are less waxy or succulent in nature than the classic hoyas are more finicky + need more regular watering.
My hoya gang respond well to regular feeding during the Spring-Summer growing season here in the UK — I feed once or twice a month, depending on my watering routine + what the temperature is like. As a note here, if your climate is quite different to mine + you find your plants grow year-round, then more regular fertilising is fine. The easiest way to judge whether or not to feed is if your plant is actively growing. Regular feeding is good practice as it can help keep your plants robust; weakened plants are more susceptible to a pest attack. I always use my feed at half the recommended dilution rate for my houseplants.
The best way to think about creating a suitable potting mix for any of your houseplants is to first consider how they grow in the wild. To help emulate the epiphytic conditions that many hoya are used to, a free draining potting mix is a good choice for indoor growing. I don’t measure my mix as I prefer to do it by eye, but I find an equal measure of either houseplant or succulent potting mix (whatever I have available), orchid bark of a medium ‘chunk’ size + perlite or pumice works really well for me.
Following on from the plant-showering point above, this method is also an excellent pest-deterrent as a moderate spray with a shower head can help keep things clean. Dusty build up on foliage (particularly of the velvety soft leaves of the linearis) can be a bit of a pest-magnet for things like spider mites. Mealy bugs are probably the most common pest to encounter on hoyas, or aphids in very warm + dry conditions. Lack of humidity + sporadic or incorrect watering is often the cause of pests on these plants. This is another reason to keep your plants away from bright light which can exacerbate these issues further. Vining plants such as these with twisting, long stems can be difficult to treat, so prevention is better than cure! An insecticidal soap spray can be an effective treatment — but check every week + isolate the plant from others until you have got the problem under control.
This is quite an important aspect of hoya care which can really make a considerable difference to the health of your plant + it’s not what you might think if you are a new plant parent with mainly ‘regular’ foliage plants in your collection. Hoya’s really don’t need regular repotting + by regular, I mean years not months. I waited around 16 months between re-potting my linearis in the photo above + waited until the roots were growing out of the drainage holes. Furthermore, they also don’t like the process either so you really can be killing your hoya with kindness if you keep disrupting the roots by regular repotting. Hoya have relatively fine, delicate roots + you can wait until they are pot-bound before repotting, which is best to do at the beginning of the growing season. Only go up one post size at a time too!
I really enjoy hoya propagation + would 100% recommend giving it a go if you are able to give your plant a little trim, or get hold of a cutting. Cuttings can be rooted in water or sphagnum moss + please note that they do take a little longer due to the woody stems (than super-fast rooters like spider plants for example) so a little patience is needed. Increased humidity when the cuttings are rooting can help to speed things up, so an old container with a lid (I sometimes use an old lunchbox!) or a humidity dome… or even a clear plastic bag can help raise the humidity around the plant. I didn’t do this with my cuttings but I have with other plants + I know cuttings in sphagnum can root well via this method.
I received my pubicalyx as a cutting — photo below left + rooted it in water…you can see the roots below right:
I have also experimented in propagating my linearis — the photo below left was from 9 months ago + the photo to the right is it this Summer!
The distinctive ‘porcelain flowers’ of hoyas are certainly one of the appealing aspects of growing these plants + you might be disappointed if you haven’t got your plant to bloom yet. Hoya blooms often adorn the pages of retro-gardening books but they do have a tendency to be a bit elusive in real life. Hoyas will often bloom as a sign of stress; usually as a result of being pot-bound (the roots having out-grown the pot) or after a bit of neglect. That’s another reason to not pot on your plants too readily — you might be depriving yourself of witnessing those signature sweet-smelling, star-shaped flowers if you don’t allow your plant to properly outgrow the pot. With that in mind, don’t try to outsmart your plant by repotting your hoya into a smaller pot to try + promote stress blooming — it can send your hoya into shock + is not good for the plant!
The other main aspect though is light, not just the duration of sunshine the plant gets every day, but the intensity of light it receives. If you want your plant to bloom, you need to find a bright enough position (whilst also protecting it from too much direct sun)… this can take a bit of experimenting but the more you learn to understand light, the more achievable this can be.
If your plant looks like it might be starting to bloom, another tip I have picked up over the years is to give the plant a feed with more phosphorus in it.
SIDE NOTE: Just as I was about to publish this post, I was having a look at my plant corner + to my absolute surprise I noticed that my linearis is starting to bloom… how exciting! This is the first time my plant has flowered so I’ll be sure to take photos + share on my instagram stories.
Lastly, we need to discuss pruning. If like me, you are happy to take cuttings of your plants to keep them looking full + to propagate + grow your collection, you need to be quite careful when cutting back your hoya. It’s fine to prune any shrivelled, dried stems, but you need to be absolutely sure you aren’t cutting off any peduncles — these can also look a bit woody + to a novice gardener, might be overlooked + accidentally cut; this is actually the point where the porcelain flowers will grow from. Also, if you have any vines that aren’t growing anything on just yet, leave them be + don’t chop too soon. My pubicalyx has a long vine at the moment that has started to wrap itself around my monstera adansonii bamboo stake when I wasn’t looking! If you take cuttings, watch out for the milky, latex sap that can be an irritant. If you then intend to propagate that stem, I like to wait a few days for this cut to callus over before putting into water, which lessens the chance of the stem rotting in water.
Phew! So there we go — a complete hoya care guide. I hope this longer post has been useful for those asking me to write it + that it helps to keep your hoya plants happy.
As a little bit of historical background to conclude this post, here’s the ‘H’ excerpt from my ‘A to Z of houseplants’ series I wrote last winter (which I’ve linked in case you want to check it out):