(Mexico (just south of Arizona))
It was doing great in the tinted window sill since Christmas. A table spoon of water in the morning & it was flourishing all these months with new pink leaves. I used Miracle grow every few weeks. Now the humidity is higher & temp hotter. It is turning yellow, drooping & dropping leaves. I live in Mexico. Currently: 90F with 72 humidity at 11am. It has been in a pot of potting soil with a little peat moss mixed in.
Hi Brenda, high humidity shouldn't affect these plants as they are native to a jungle setting, not in the desert.
However, I wonder if the heat is a problem for them. They require good air circulation, as you can imagine up in the treetops they would have all the breezes, so maybe try and get some air circulation happening.
You don't say if you have air conditioning, but if you do, make sure the plant isn't near cold air blowing on it.
These plants (known botanically as Schlumbergera do require a dormant period where they really prefer to dry out a lot, until the late summer when you can water them more.
It's also possible that there is root rot happening (pull the plant out and have a look at the roots - healthy roots will be white or pale colored, rotting roots will be dark and shriveled looking).
It sounds as though you're using a potting mix that it should like, with some organic matter in it. Keep in mind that epiphytes are not like other succulents and do require a more organic mix, such as leaf mold or peat moss.
Now that they should be going into a dormant period, maybe flush out the soil with fresh water (rainwater is the best) and then don't fertilize any more until after growth starts again in the fall.
Without seeing a picture of it, I can't really help with this issue, but maybe one or more of these suggestions will help.
Best of luck,
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