I’ve spent a LOT of time researching orchid care, but I’ve found most of the intro advice lacks detail and isn’t very helpful for indoor growers. In this post, I am presenting the underlying details for successful orchid care that I use, so that others like might experience similar success with their plants.
About my conditions: I live in Canada and grow in a condo that often has very dry air (under 50%)—if you live somewhere humid, take the advice in this site with a critical eye as the conditions I grow in, are not the same as yours.
Plants need food to grow big and strong—but it doesn’t have to be complicated. As a starting point, adding fertilizer at 1/4 strength during each watering (that’s generally 1/2 tsp/gallon of water) is a good baseline. Any balanced fertilizer will do (20-20-20); but be aware, many orchid ferts are generally geared toward blooming (and less toward growth); MSU Orchid fertilizer is an ideal balanced fertilizer made for orchid growth—but again, “regular fertilizer” (20-20-20) at 1/4 ratio works well too.
2) A Good Potting Mix
I recommend “Orchid Bark” and a bit of sphagnum moss (if you can find it). A ratio of about 80% bark to 20% sphagnum moss is good because bark allows for good air flow while the sphagnum moss keeps the mix moist a little longer. If you can’t find any sphagnum moss, you’ll likely have to water more often. It’s even better if you can add an additional 30% of perlite or pumice (but if you can’t find any, that’s okay, just repot every 8-12 months). I also recommend top-dressing each pot with a thin layer (1/8-1/4″) of sphagnum moss; this layer helps keep the base of the plant (where new roots are starting) moist and a little less harsh.
Knowledge is power: I’m big on understanding the overarching concepts in life; it means I don’t have to remember every single detail—my brain just doesn’t have the space for every little detail…
The takeaway for creating an ideal potting mix (FOR ANY PLANT not just orchids) is to balance organic (water-retentive) media with inorganic (porous) additives and encourage a wet-to-dry cycle where the mix is evenly moist and approaches dryness, but is never allowed to go BONE DRY.
Your goal is to achieve an ebb and flow of water and oxygen through your potting mix and keep the medium evenly moist while also open/well-oxygenated. Stagnant and compact conditions In the mix are bad because it kills roots—when oxygen is low, anaerobic bacteria thrive and that causes problems. Organic media (bark, sphagnum, peatmoss) are more ideal because they hold water and release it over time (increasing humidity around the roots). Organic ingredients also promotes beneficial bacteria which can aid in the breakdown of some types of fertilizers into usable compounds. Too much organic media can result in compacting as the medium breaks down over time, so you want to add inorganic and porous additives. Inert or inorganic compounds (such as perlite, pumice, volcanic rock, and charcoal) are helpful because they prevent the media from collapsing around the roots and they promote air circulation and good water flow even if the media starts to degrade.
Some growers use only inert / inorganic potting media (no bark/ no moss), but that creates challenges if you’re growing in a home where the humidity isn’t ideal (under 65% rH). Most orchids aren’t lithophytes (plants that grow on rocks); they have adapted to grow better in less-harsh conditions…that’s why I’m a proponent of a blended mix over an inorganic mix alone. You need a blend of both organic and inorganic compounds to keep the roots well-hydrated but also oxygenated and healthy – It’s a tricky concept, but once you get it, it’s pretty much a guaranteed success.
As you get better with understanding each extreme, you’ll be able to adjust the ratio of organic and inert materials to customize the drying rate of your media and better-tailor your media to each individual orchid species. For faster drying, add more inert materials. For more evenly moist conditions, add more organic media. Understanding how to adjust these ingredients in your orchid potting mix gives you the ability to ensure the “quick-dry” orchids get an ideal media, while also offering what the “always moist” orchids need, even though you may be growing them side-by-side on the same shelf.
“Low light” doesn’t mean “no light”—if you can, place your plant at an East window where it will get some direct sun during the first 4-5 hours of the day (while the sun isn’t so hot it will burn the leaves). You want light shining on your leaves where possible, but ensure the leaf-temperature is cool (touch the leaf – if it feels warm, that’s not good and you should put up a sheer cloth to reduce the sun’s intensity). If you have poorly insulated windows, direct sun can be very hot. Keep in mind, just because you move the plant away from the window (and out of the heat), does not mean it’s getting enough light. It’s a tricky balance and you need to find the “just right” area where it’s bright enough, but not so hot it burns the leaves. When in doubt, use a sheer curtain or UV filter between your window and your plant to screen the sun’s intensity; this way, rather than moving them away from the windows into the 100% shadows of your roof, you can actually provide “dappled sunlight” like they would receive in a forest.
A story: I have nearly all my plants directly at the windows. There are 4 plants that are about 6 feet away from the windows – the room is still visibly bright…but those orchids deeper in my room grow much slower and flower less. So my lesson to you: light is the most important aspect of orchid culture. Make sure you provide enough of it, but avoid burning the leaves.
Photos of various orchids & phalaenopsis at an East-window in direct sun
Saving the best for last; the most important aspect of caring for orchids is keeping them hydrated. If your humidity is low, it’s not the end of the world provided you can water them at consistent intervals. This doesn’t mean you water them more often, and this doesn’t mean you let them sit in water for days either. You want the plant’s roots to approach dryness at every watering cycle, and THEN you want to water liberally. Wet, then approaching dryness. Wet, then approaching dryness. Get into a regular routine of this wet/dry cycle and you’ll have a better chance at success; just make sure the potting media is nearly bone dry in the lower layers before you water again.
If your potting mix is good (as outlined above), once a week is generally sufficient for a good watering; sometimes smaller plants, or newly potted orchids will need to be watered more often and occasionally old media, or on cool winter weeks you’ll have to water even less often. If you’re finding the mix is always drying too quickly, you can soak (yes SOAK) your orchid in a bowl of that quarter-strength fertilizer water (mentioned in point #1) for 5-15 minutes. If it’s taking too long to dry and it’s been a while since you repotted…consider repotting your orchid. Always make sure you drain all the water before you put them back on the shelf.
It’s a good idea to thoroughly rinse the bark/pot either before or after you fertilize with regular water. It’s a process called, “leaching” your pots. The act of drenching and flushing your orchid pot with “regular water” (no ferts) will continuously get rid of any remaining fertilizer, or salts that otherwise would progressively build up in your mix. If you want to alternate the soaking of fertilizer water one week, to regular water the next, that can also help to reduce the buildup of salt in the mix—I’ve done both; the trick is to soak the whole pot, then drain. After you’ve let the plant soak and you’ve drained it, let it drip-dry for another 10 minutes, and discard any additional water (do this twice for safe measure – you don’t want any remaining water sitting in the bottom of the pot); then put it back by the window.
Are you a stickler for details?
Here is my very detailed post which includes EVERYTHING I do for my plants from light to fertilizer and more.