I would only mist them in the day time. Spider mites cause yellow patches on the leaves.

Thanks. I had spider mites on an aucuba, and the leaves turned yellow. These palm leaves are turning brown at the tips, and some even further in.

I don't think misting them during the day time or night time would make any difference at all. Zzackey, any specific reason you'd say that? Curious.

in fact misting doesn't do much at all. If you want to increase humidity, get a humidifier and a hygrometer. I've found that misting only seems to slightly help keep spider mite populations down.

i wouldn't base the leaves turning color on spider mites. If you have webbing and small brown / black dots about the size of a grain of salt that move, that's when you know you have spider mites. If you do find them, spray with a mixture of 50% water and 50% isopropyl alcohol (the 70% version).

I'd look closely as to how their care may have changed after your surgery.

Here's a photo of the largest plant, which I've had since about September. Until my surgery a month ago, it was a healthy green plant. In the last week it's rapidly declined, and I now have to throw it in the trash.

The only thing that's changed is that I wasn't able to mist it. I still watered it, although I did so in place rather than in the sink. I used rainwater or distilled water.

I started using rainwater or distilled water about 6-7 weeks ago. Before that I used tap water, which is very hard here.

I suppose it's possible that, with January being the coldest month here in Alabama, it was also the driest indoors. I can't think of anything else.

Here's photos of the largest plant (the worst) showing the affected leaves.