Yes, Hoya are epiphytes BUT they grow in a slightly different way to other epiphytes, like orchids and aroids.
It’s quite common to see epiphytes like moth orchids grown without substrate, but I don’t think I’ve ever seen anyone grow Hoya epiphytically. Perhaps I should give it a go!
What are epiphytes?
Epiphytes are plants that grow on the surface of another plant, rather than on the ground. Another common epiphyte is the bromeliad.
Aroids like Monstera are actually hemiepiphytes, which mean they start off growing on the ground, and then grow up into the trees and attaching to trees as they mature using their aerial roots.
Hoya don’t produce aerial roots as such, but they do produce adventitious roots along the stem that allow them to absorb more water.
Ok, this is a lie. Some Hoya DO produce aerial roots, others, use their runners/vines to climb.
Source: me. I bought a Hoya kroniana and it had aerial roots.
Are all Hoya epiphytes?
No, but most of them are. You’re unlikely to stumble across terrestrial Hoya unless you go looking for them, but Hoya eriostemma is one you could try. They are…er, green. The blooms are cute though – they look like little stars.
Should Hoya climb or trail?
Due to the nature of a Hoya’s growth pattern, you can have them trail or climb.
In the wild, they grow in the crook of tree branches, and they’ll typically climb to find more light. In the home, they’ll move towards the light and then wave around looking for something to attach to.
When they find something to attach to, they’ll spiral their tendrils around it.
They do not care whether they’ve actually found support or just another runner from the same plant:
Not entirely sure how that one’s gonna work out.
In general, I let Hoya do their own thing. Most of them are in great light, so they’re looking for support rather than light. The one in the photo above is in a north-facing window, hence the up and over approach towards the window.
However some Hoya, like Hoya bella and Hoya linearis are definitely more suited to trailing than climbing. They don’t tend to vine – they just grow longer, so if you’re after a trailing plant, I’d definitely recommend either of those.
Bella for the blooms, or linearis for the unusual shape (they also bloom, and they’re great if you need something that will stay long and thin).
Can you grow a Hoya epiphytically at home?
Not properly, unless you’re VERY committed (or have a terrarium with a sprayer/fogger), but you can grow them bare root.
I grow my phalaenopsis bare-root but that’s quite easy because the roots go green when it’s hydrated. I soak it until the roots go green, and then wait until they’re pretty much all silver again and repeat.
Hoya roots are much smaller and finer and don’t change colour.
There's no easy way to tell when they need watering again BUT I suppose we could assume that they'll need watering approx as much as a moth orchid, so you could get one orchid to tell you when to water, and then water your Hoya at the same time.
Hoya like to drink deeply, so I’d definitely go the soaking route over the spraying route. Unless you have nothing better to do than thoroughly spray your Hoya daily, in which case knock yourself out.
If you plan on soaking your Hoya, then I highly recommend making it easy to soak, so make sure you’re growing it somewhere that’s easy to access.
What I’m saying is don’t buy a big tree to grow your Hoya because when it attaches it’ll be a nightmare to water.
You COULD keep them in a terrarium, but Hoya do like to dry out a bit between waterings. If you did go the terrarium route, you’d need both high humidity and great air flow, so it wouldn’t;t be as easy as shoving some soil and a plant in a box.
The great thing about Hoya is that they have small root systems, so you could buy a small piece of driftwood, and attach the Hoya to it using string or pipe cleaners. Soak it every week in water, and add nutrients to the water every other week.
(By the way, I’ve found that skipping watering for a month in April results in maximum blooms)
Over time, the roots will attach to the driftwood, and it’ll look VERY cool. Just make sure the wood is small enough that you can soak the roots easily.
I highly, highly recommend doing this at the end of spring so the hoya has a chance to get its roots established during the growing season. I would also start with a small Hoya (or even root some cuttings of a Hoya you already have because these things don’t always go the way we want them to.
Final thoughts
Whilst Hoya are epiphytes, most of the time they’re sold in potting mix. However, their epiphytic nature means that they’re pretty tolerant of under-watering (they have pretty succulent leaves) and will succumb to root rot quite quickly if they’re watered to frequently.
I personally find they grow and bloom best if you stay fairly on top of keeping them hydrated. I check my Hoya’s soil weekly to see if it’s dry, but most of them only need watering once a week, even in the middle of summer.
The only exception is my Hoya Krimson queen, because it’s in a bright window and the soil is exposed to the light. The Hoya Parasitica black margin next to it stays damp longer because the soil is covered with leaves. You wouldn’t think it would make that much of a difference but it really does:
Was that picture necessary or am I just showing off the pink leaves? Who knows.
