The majority of orchids we keep as houseplants are epiphytous, which means they grow not on the ground but in trees. In this post, when I speak of “orchids”, this is the kind of orchid I will be talking about. There is one notable exception which I will bring up at the end.
First of all, let’s talk about how “orchid” is not synonymous with “Phalaenopsis”. Pictured above are an Oncidium, Cattleya and Dendrobium, all of which sit in my window and flower regularly.
More Than Just Phalaenopsis
Don’t get me wrong, I love a nice Phal. There’s an incredible variety of flower shapes and sizes to be found these days; from the enormous, white flowers associated with weddings((In Swedish, they’re often referred to as “brudorkidé” or “bridal orchid”)), to miniature ones with sprays of multicoloured blossoms. Phals are incredibly easy to care for and will often produce new flowers on old stems – so don’t cut them off until they’ve dried up!
But although they definitely have their virtues, I still think it’s a pity that a lot of people equate this one family with the entirety of orchid-kind. There are many others. Some are very difficult to keep as houseplants, but many will be quite happy sitting in a window sill. Most of them have beautiful flowers, but I personally like them just as much for their different growth styles, leaf shapes and colours.
Light and Water
Let’s start with the basics. Because orchids grow in trees, they are adapted to a fairly bright environment, but usually prefer filtered to direct sunlight. Windows are a good place for them, but be careful of midday sun if the window faces south, or their leaves may burn. I protect my orchids during the brighter months by setting up a screen of semi-transparent white fabric.
To make sure your orchids get enough water, it’s usually best to submerge the entire pot when you water them. Either bring a bucket to where they are, or bring your orchids to the sink. Dunk the pot, keep it just level with the surface until bubbles stop rising, then lift it and wait for the excess water to drain. It’s fine if it’s still dripping a fair bit when you put it back in the outer pot, so long as you’re using one specifically for orchids (see below).
I water my orchids once a week. In the winter, the usual advice is to do it every ten days, but this would screw with my routines. So what I do is dunk the pot every other week, and every other just top up with a bit of water from above.
Since their potting mix (see below) doesn’t have very high water retention, orchids thrive best with high humidity. If the air in your home is very dry, consider setting out a few bowls filled with pebbles and water among your houseplants. Or, even better, find a large tray, spread pebbles, perlite or similar on it, fill it with water and set your orchid pots on top. Also, orchids love regular showers. Either mist them with a spray bottle or take them into the actual shower every once in a while – the latter will help keep the leaves dust free, as well.
As for nutrition: Just like orchid roots are sensitive to waterlogging, they are sensitive to overfeeding. Using regular plant food is fine, but dilute it a few times extra to avoid burning the roots. As with regular houseplants, it’s generally best to supply extra nutrients only in the spring and summer, so as to not encourage growth when there’s a light deficit.
Pots for Orchids
Some orchids need to be grown in “cages” hanging in the air to thrive. These tend to be rather a lot trickier to care for and are thus not suitable for beginners, which is why I’m not dealing with those in this post.
Most orchids however don’t need special containers. I keep mine in regular plastic pots. They do just fine in terracotta, but keep in mind that terracotta is porous and the roots may attach themselves quite firmly, requiring you to damage them when repotting.
One thing to consider is getting special outer pots for orchids. These are taller and narrower than regular pots. They’re designed this way to keep the inner pot up and off the bottom, which makes sure that the roots don’t get waterlogged. At the same time, letting a bit of water sit at the bottom helps keep the humidity high in the air around the roots.
This rather peculiar adaptation to living in trees means several things – their roots often grow in all sorts of interesting directions, and they do not enjoy a regular, nutrient rich soil. To keep an orchid happy, you need to acquire special orchid potting mix. This consists of a very rough compost, usually made up of pieces of bark mixed with peat.
Orchid compost is easy to make yourself if you have access to raw material. Pine/fir bark is perfect, and dried sphagnum moss makes an excellent replacement for peat((Peat is a barely renewable resource, whose extraction upsets ancient ecosystems. As such it really should be avoided.)). But orchids really aren’t that picky; people grow them in all kinds of substrates, including old corks, coconut husk, sticks, perlite and tree fern fibers. Some materials may require you to add more fertiliser than others, and there’s obviously a huge difference in water retention.
I won’t go indepth about this – the internet is full of information, and for beginners, store-bought potting mix will be fine. However, you may want to pay attention to how “chunky” the mix is. If it’s only got very small pieces of bark mixed with lots of peat, it may become waterlogged. Conversely, if you are repotting an orchid with very fine roots, a mix that is too coarse will be difficult to work with and may end up damaging the roots. Generally, the thicker the roots, the chunkier you want the medium to be.
You may have seen orchids growing directly on pieces of wood. While this is very pleasing to the eye, it requires a very humid climate to work. Most indoor air is too dry and will require you to mist the orchid daily, at the very least.
As noted, orchids grow in compost, and a key feature of composts is that they decompose. This process releases nutrients to the roots, but also means the substrate becomes more finely grained. On top of this, a thriving orchid will fill up its pot with roots just as well as any other plant. Thus, it’s a good idea to repot your orchids regularly, or roots will start choking and rot may set in.
Repotting is best done when the orchid is in the beginning of a growth spurt, so that it’ll quickly settle into its new substrate. This will usually be in the spring, but can be any time of year. Check the roots: If they have pale green tips, that means they’re currently growing. Be careful though, this means they’re sensitive and may break off easily!
Repotting orchids is done much the same as with other plants: Soak the entire pot for a while, then carefully dislodge the plant. Remove as much of the old compost as you can, and cut off dead roots at the same time. Orchids are great in this regard, as you can easily identify dead roots by gently squeezing them. If they feel empty and collapsed, they’re dead. If they’re stiff and resist pressure, they’re probably alive.
If the plant has outgrown its pot, give it a new, slightly bigger one (or divide the plant, if its growth is modular). Some orchids expand by setting new bulbs, and often do so in a certain direction. If so, make sure to set the opposite end of the plant at the edge of the pot, so the orchid has lots of space to grow. Do not force any aerial roots into the pot, just leave them where they are. Fill any empty space with potting mix. Shake the whole thing occasionally to get the mix to settle into place between the roots. Then submerge the entire pot in water for a while, and you’re done!
The Exception That Proves the Rule
There are plenty of orchids that grow on the ground, but these are normally not kept as houseplants. One ground-living orchid that is often kept in a pot is the Ludisia. Most people won’t even recognise it as an orchid, it’s so different from what we’re used to.
Since it grows on the ground, you keep it in regular potting mix and treat it as any other houseplant. It’ll stop growing if it dries up too often, so consider covering the soil with mulch.
And there we go! As always, there’s much more to be said, but this post contains more than you actually need to know to keep the easier varieties alive. Hope you enjoyed, and that your orchids will thrive in your care.