Potted palm tree has brown tips

Hi,

Bought this small potted palm last spring. It did fine on my porch (Virginia) during the summer and fall, but developed these brown tips over the winter. It has been outside for a few weeks getting partial sun and the brown tips seems to continue to spread. Any suggestions? I keep it watered, although haven't fed it. Any ideas what causes the brown tips in a palm?

sorry - here's the pic