It took us a long time to find Calathea orbifolia! Plus after we found them, I made sure I cared for one in my home for a few months before we actually put them up for sale. I'd heard so much about how picky they are, I wanted to make sure I was really comfortable with their care before we sold them! So, here are our care recommendations based on my personal experience with them both at home and in our greenhouse:
Light: Comparable to other Calathea with smooth, shiny leaves (like a Rattlesnake), these guys do like a decent amount of bright indirect light if you want big leaves and lots of growth, but any direct light will burn them.
Water: Keep the potting mix moist but not soggy. For me, with 4" plant that isn't root bound, that means watering every 3-4 days, but remember to go by the feeling of the potting mix and check in with your plant regularly, not a set schedule.
I used tap water and didn’t have any issues (and we have pretty terrible water!) but I know a lot of people swear by filtered or distilled water when it comes to Calatheas. I use tap water for all my plants in my home and greenhouses, and what I've found is that a well cared for plant (one that's getting the right amounts of water, light, and humidity), rarely needs distilled water.
Humidity: I find it’s fine if I keep it clustered with at least 2-3 other plants. Super dry areas (I’m looking at you, Utah), especially in the winter with all the extra dry air from heating systems would probably need a humidifier.
And there you have it! They're far from the pickiest Calathea I've cared for (that would be the Zebrina), but like all Calathea, they do need a spot with just the right light and their potting mix will need to be kept moist.