Cold soil is likely the reason, unfortunately.

I think it just got stunted by the cold i have 1 doing the exact same thing that defoliated too.

Thank you both for your help.

Flattie, I can't see how it could be cold soil, because the soil is no doubt warmer now than it was when the palm was growing back in april and may.

Topher, it could be that it got stunted by the cold, but its been through 3 winters in the ground here in Michigan, and it has grown more substantially than this in the last 3 growing seasons.

Could it possibly be too much fertilizer? Or maybe fertilized too early? I fertilized with a granular fertilizer when it started growing in late April. I'm just hoping it has enough energy stored up to make it through this next winter...Or maybe it is just rooting? I transplanted it in August of last summer.

I have heard many times that the season after a complete, or near complete defoliation, that they always grow very very slowly. If it does not defoliate again this winter and comes through fine, then you should see much better growth next summer. Plants get ALOT of their energy for growth from their leaves, so perhaps it maybe only put up enough leaves to produce enough energy to put into more root growth. I would tend to think that once it fully recovers it will be fine. Just a guess really, but thats my .02

I guess I'll have to make sure it doesn't defoliate again this winter then...

The thing that baffles me though is that it was growing pretty quickly through April and May, but from June on it stopped growing completely. Its not even a matter of growing slow. I'm baffled.

This winter I'll just have to use christmas lights and double bag it I guess.

Island breeze
That's a funny thing with these you may take cold damage and not even know it until months later. Mine did the same thing.

I suggest a litle more then christmas lights and plastic. If you want it to grow more it must be healthy come april. If not you will go through the same growth problem. Im from ohio and mine stays above 45 degrees all winter. Bill

I am not sure why your palm has stopped growing, but it is certainly worrisome. Your palm will most likely give up on life if it should defoliate again. These palms seem unable to recover from multiple defoliations. It is as if they run out of gas if they get winter damaged too often. The Mexican Fan Palm is not as hardy as the Windmill, but does have the stamina to quickly recover from a defoliation.

Thank you all for your ideas and thoughts. I agree, I have been letting it get too cold over the winter, definitely pushing it to its limits, and I should keep it warmer. Even if the cold isn't the problem, extra protection won't hurt.

I think maybe I'll add more lights for more heat, maybe wrap them in a spiral on the ground, and wrap the trunk in burlap to hold the heat against the trunk.

Last year, I just had 2 floodlights pointed at the ground along with covering the whole thing with a large plastic furniture bag. But on the coldest night last winter, I wasn't home to turn the floodlights on and I think that's what caused the defoliation. I think we got down to about zero degrees F.

This winter I'll have to be a little less careless and a little more proactive.