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My Calatheas almost bit the dust this winter. My C. Roseopicta's leaves curled up much like yours are doing in this picture. My understanding is that the curling is a response to low humidity and/or sudden drops in temperature which can be cause by cold drafts.
I agree with everyone here when they recommend you get a humidifier. This humidifier is cheap and easy to clean.
However, my situation called for a more drastic approach. Even with the humidifiers going the humidity regularly dips to 25%. Had to build a makeshift terrarium. I bought a translucent tote, threw about an inch of LECA on the bottom, added distilled water, put a 1020 tray over that and put my calatheas in there. The humidity in there stays somewhere between 80% to 100% and they're safe from hot or cold drafts. My C. Roseopicta's leaves opened right up. Today I'll be installing a small fan to improve air circulation to prevent bacterial/fungal problems. I think of it as a calathea hospital. lol
Winters are brutal for Calatheas. OTOH my monstera, tetrasperma, anthuriums, aglaonema, spaths etc. are unfazed.
Check out my newest post! I’m running one of these solo in this same 2x4 tent now, but for flower, while the other 4 are in my new 4x4.
The humidifier I was using in this picture had too small of a tank so I just changed it for this one which I highly recommend: