I suggest less misting, instead increase the relative humidity in the room. And let the soil begin to dry out between waterings. Your current setup, without natural direct sunlight, is a recipe for a fatal fungal disease.

Many of us lost our spindle palms last winter due to similar symptoms. Sometimes there is nothing you can do.

What temps did it get hit by before you brought it inside? The first pic looks like frost damage to me, but the spear would be done as well, not just the lower branches. Even with a daylight bulb, it might just be shut down for winter, and the "damp" soil and warmth is trying to get it to grow? If you didnt acclimate it to indoor conditions, it could just be reacting to lack of light?

It was brought in well below any cold weather. One frond had bit of spider mites, but misted that with alcohol/soap mix and wiped all fronds off with towel soaked in Neem oil. That was a couple of weeks ago, and no more spider mites. All plants around the foxtail were sprayed with same solution too, and all look ok. That was when Foxtail was in different room, facing the West, with bright ceiling light left on all day(halogen). Of the 20? plants in that room, all are fine except the Foxtail.

The damage started from lowest frond and has been working it's way up so far.

Do you have a guess at the lowest temp? Even at 5C some plants may get damaged.... Also, did you acclimate it, as it sit it in some shade for a week or 2 before bringing it in?

Oh, maybe 45? Never saw any frost or real cold.

Palm sat in full sun pretty much and loved it outside. Could almost watch the thing grow! No, didn't put in shade first. Humidity in room it WAS in, is always around 50-60% Room now? maybe 50% since there is a radiant heater in that room, but again doesn't seem to bother other plants.

Not sure if it looked like over fertilization at all??

It could just be acclimating to indoor conditions. After getting mites, and the spray routine, it was just stressed maybe, and is in a slow decline before it perks up? My rubber trees always do this, especially my F religiosa.

It could be resurgance of the spider mites or a slow reaction to the spray regime?

Id let the pot dry out a bit, then throw it in the shower and flush the pot, to remove the salts from fert, and any residual chemicals and soap from spraying. It might be as simple as it being just too wet?

So leaves can dry out from soil being too wet? I know fert damage can cause that.

Im thinking rot, like Adam suggested. I just cant remember if that kills the top leaves first, or the bottom. I do know, as a general rule, most houseplants like the soil to dry out a bit before watering.

It could be as simple as foxtails being hard to grow indoors... Maybe PM barb, or wait for her to pipe in, seeing as she has one about the same size as yours.

Another possibility? Could it be root bound? When I bought this palm I didn't transplant it and simply put grow pot it came in inside another pot that was bigger around, and filled the space between the pots with pea gravel for stability and weight since it was outside.

Just pulled the grow pot out from inside the larger pot and noticed roots trying to come out drain holes at the bottom of the grow pot. Brushing away the pea gravel sitting on top of the grow pot and sticking my finger in the soil I can tell it's "damp" but hardly wet. My moisture meter is really sensitive and almost always tests "wet" in just about anything I have. Now I wonder if maybe it's so root bound that water wasn't making it to the bottom of the pot.

Hi Scott,
Foxtails hate to come inside.
But they'd croak outdoors so there's no option.

Mine does similar stuff to yours on coming in.

Cut off that oldest frond...the ugliest one, had a bad case of spider mites.

72 is too warm.
I'd put it in the coolest room possible--maybe an unused room, and block off the heating but give it brightest window there.
65F and even a bit cooler is best...and no more watering for a month.

Repot only in spring.
If root tips are coming out the bottom, that's not a problem, as root tips will die as they hit the air.
The rest of the roots will be fine.

There's a direct relationship with daylight/strength and temperature.
I'm still working on finding it exactly.

All palms have a lower frond or two that dies off annually...it's when the spear dies that you're in trouble.
Just cut off the dead frond when it's completely brown (wait past the yellow stage).

Good luck.
Barb

So maybe basement? it's cooler down there (mid 60's) but also doesn't get much light as only has two north facing windows.

I'd opt for the basement, with a full spectrum grow-light bulb.
Easy to screw into a trouble light cord suspended two feet above.
14-16 hrs a day on a timer.
At 60F, it won't need misting except very lightly every couple of weeks.

There's just no way to please Foxtails; so finicky when they come indoors. 🙄

Mine hates it in the cold barely-heated building.
We'll see how it does its first year there.
New spear came to a full stop, not growing.
But no spider mites.

Good luck with it Scott.
Barb

Yea, the newest spear I have stopped pushing as well. Just hate seeing all the fronds dry up.

How cold does it get in your building? Maybe I should over winter mine in garage with the rest of the palms I have out there. My garage never drops below freezing, but not sure if that would be too cold for my foxtail.

Like I said, Scott, it's the first year in the cold building.
So it's pretty iffy too.
A few days ago it was at 9C which is 48F (but it's been a bit colder... 😕 )

It's the SUDDEN moves (20 degree drops/increases) of a new location that is bad.
I'd go with the basement versus the garage.

Barb