I think any grow light would be okay, but coconut palm trees require a lot of light so you might want to put them by a window with direct sunlight and then maybe grow lights as well. They should do fine with just grow lights during the months they are indoors, but when they go back outside for the summer, the uch stronger sunlight could damage the fronds.

Good luck! Hopefully someone else is a bit more knowledgeable about grow lights than me since I have never really used grow lights before.
-Alex

the grow lights or sunny window may suffice for the cold months, but cocnut palms will need at least direct summer heat and sun each year.

Don't forget that the air can be extremely dry
right next to the lights which may burn the fronds.

Yes, humidity is definitely a huge factor in keeping coconut palms happy. I water mine very little indoors, but constantly spray the fronds with water.
-Alex

I have a coconut palm in a pot that I've had for about 3 years now. It stays in my bedroom during the winter next to a south facing window so it gets plenty of sun. I had 2 before that.

The first died after I tried to winter it in my garage. Too cold and dark.

The second one died the next winter in my greenhouse. Plenty of sun but still too cold. The heater doesn't come on until it dips to 40.

Humidity has never been an issue with them. It's always been temperature. They do NOT like prolonged cold.

Mine stays on my deck in partial shade all summer long here in North Central TX. Even after this last record dry, hot one. It's looking great and is about 7ft tall including the pot.

-Stacy

Hi Stacey,

Another trick I learned while growing huge coconut palms in zone 7 was to water them with warm water 78-82*. I do it for my citrus now and they love it. Many of these plants do not like cold water but tolerate it well in the summer but catch cold in the winter.