Sounds like lack of humidity and possibly an issue with spider mites. I'm wintering several palms and bananas indoors at a retail store I own. I've been learning along the way also... Among the similar palms I have, an almost 5-foot 4-trunk pygmy date and a 4 1/2 foot washy. Ironically both the washy and pygmy are doing as well as any of my palms, actually excellent. We are colder here and the hard cold hit earlier and it is very dry indoors. These are growing very well under bright florescent lighting, they really seem to like it. Wasahy/pygmy: Water, water! Mine seem to drink like fish. I literally have to water the washy every day, or every other day at the least. If not it gets the tell-tale droopy lower fronds. Keep it watered and it is opening a new fan every other week and growing like mad surprisingly! I still can't believe how fast my washy is growing in a pot indoors, it's amazing. Pygmy date seems to be a heavy drinker also, definitely keep it well watered with clean, preferably home-distilled water. I mist these palms, along with all the palms in the store, about 2x a week. It is quite a job, takes me a good hour to get to all of them! Also wintering indoors are many large basjoos, trachys, xmas palms, etc. These all love to be misted and well watered. Check for spider mites. They can be hard to spot on palms. I did have a smaller trachy get them, caught it on time and its doing fine now. Look for those little spider webs... My basjoos got attacked bad early in the winter. I got it under control eventually with a little trial and error. They look great now that new leaves have replaced the chewed ones and have been able to be pruned. Again, water, water, and mist for these! My largest basjoo which has 4 more pups now is in danger of exceeding the 14' ceiling in the store. I don't know what I'm going to do if it does before I can take it home and put it back in the ground this spring. It has slowed to putting out one new leaf a week but they are in excess of 6 feet long and at least 2 feet wide. Most of my other bananas ranging from 4 to 8 feet tall are still putting out a new leaf every 3 to 5 days now. I'd also advise against fertilizing them during the winter. Good luck with your palms! P.S. If you have spider mites on palms, Home Depot carries the stuff I use on palms and bananas. It works AWESOME and is actually labeled for use on palms and others. Volck Oil Spray (concentrate). About $5 for a bottle which makes something like 30 gallons mixed. One or two treatments and they are good for the winter. Killed all the mites on my bananas and little trachy, have not seen any mite evidence for a long time now with just 2 treatments. My bananas had them BAD also! Shines up the leaves and makes the plants look real good also.

David, these three and other palms go into a detached, two car, loft garage from December 1 to March 1. Definitely, NOT a palm for indoors, too dangerous. I had to saw off the tap root on these as they have a tendency to find cracks in the blacktop and grow into the ground over the course of the growing season. Remember, these guys grow in very arid regions so roots have a tendency to go deep seeking out underground water/aquifers (so deep pots are preferred). Big misconception is that date species from arid regions don't like much water, NOT TRUE. And some date species come out of tropical regions with monsoonal rains. Phoenix is a nice genus of palms but most are not for the house, with the exception of the Pygmy Dates (Phoenix roebellini).

Polar bear, I only have a handful of palms that get sooo big eventually that they get thrown out of the house...Phoenix, Washingtonia, Butias, and Tracycarpus. Sure, pot size will constrain their growth, as will a lack of optimal growing conditions...SUN, HEAT, FERTILIZER, and WATER (in the growing season). If you want something faster from seed, try Washingtonia Fan Palms (many of mine started from seed). I also suggested the feather palm Butia (they grow like weeds on steroids!). They are quite cold tolerant btw, so as long as get are freezing or above, they are fine in their Winter abode. Occasionally, they get top dragged out in midwinter to get hosed down, or I will cover their contains with snow to get some moisture, but they are largely dry, dry, dry, in Winter. I like them too, they don't seem to mind NJ's ridiculously high Summer humidity and rain, as do many Phoenix/Date palms. I see your palm is inside from your post. That us one reason you are seeing slower growth. They really are not indoor palms... They wanna be outside in the sun and other elements. Mine are out from about March 1 to early December. Adults are okay with some degree of frost and our growing season, even heat, tends to linger well through Autumn.

Handsome little guy you got there! I have a couple and mine seem to do fantastic up here. They do live outside from April until October though, and LOVE IT! When I do bring them in they are in large south facing windows, with no shades during the day time. They do love full sun so I would recommend that you open the shades for it during the day. The more light the better. As for the roots, that is no problem at all. You can if you like always plant it slightly deeper in the pot so the bottom of the trunk sits on or just very slightly below the soil level, covering up the exposed roots. Both of mine have a significant portion of the top of the root ball that is above the soil line, and they are completely unaffected by it. In fact my 6 foot tall has adventitious roots completely covering the first few inches of the trunk, and it is completely fine. The only real issue with leaving it as it is as that as the trunk gets bigger/ taller it could become slightly less stable, but that is really the only negative impact I can think of. Nice find and good luck with it! Keep us up to date on how it does. These are one of my favorite palms!