I've had the ZZ plant for almost a year now. I have kept it in the planter pot in came in, and just placed it into a white decorative pot.
It was originally by a south facing window set back by our balcony in front of it for rather indirect moderate light. It was placed on floor level and was very upright and growing very quickly for a period of time. I knew that overwatering was a concern so I only watered every 3-4 weeks when the top soil was dry. I would take the plant out of the decorative pot to water and let it drain before placing it back.
Around December, I noticed that some of the stems were starting to droop and a new growth at the base turned yellow pretty quickly. I thought it was a watering issue and watered less frequently (every month or longer). However, this did not improve and so I moved it closer to my larger south facing window that didn't have a balcony in front, so it had more light during the day (see picture with white decorative pot). In less than 2 weeks, I noticed that the stems drooped even more and the leaves started to curl. I moved it a bit further back from the light thinking it may be too much sun (realizing only recently that winter afternoon sun is lower and more intense than summer months). However, after giving it a couple of months, this did not seem to improve and slowly became more droopy and more curled (see picture with pot further back).
Finally, we moved it into the bedroom at the end of March which has a south west facing window, but set 10 feet back from the window for very indirect soft light throughout the day. Watering was kept to every month or so (at times even longer in between). Two weeks ago, I was repotting my plants and decided to repot the ZZ with some new potting mix since the existing one seemed to be quite dry (e.g. water drained straight through right after I'd start to water it). I kept it in the same pot (washed the pot of the old soil) and size as I wasn't sure whether it should be potted into a larger size.
The pictures in its black planter pot show what it looks like now... basically all drooping and pulling out of the sides, and very curled across most of the stalks, some very tightly curled. There are only one or two stalks that still have a deeper green colour and less curls, but even today I am noticing its colour fade and starting to curl.
ZZ is known to be a low maintenance plant, but it has been a good several months of watching it... and I can't seem to quite figure out what I might be doing wrong
. Any help or insight would be very much appreciated! Thank you!