Does it have any part of the rhizome or bulb on it? If so you can just plant it. I would probably pot it this time of the year if there is a chance of freezing temps.
If there is no bulb at all, it might not root but you could try a little rooting hormone on the stem and trim most all the leaves off and plant it that way. I have 'heard' that some people can root ginger stems in water. I tried this with my globbas without any success lol. Maybe someone else has more info on that.

Hi Jasmine, Thanks for responding. Yes it does have a bulb. Here is a picture of it. So all I have to do it just pot it up? About how much of the leave should I trim?

This post was edited by rmcandlelight on Tue, Feb 11, 14 at 13:16

If it has the bulb I would go ahead and pot it up and add some perlite to your potting mix. Keep moist but not soggy.
Since the bulb is so small it might be a little top heavy so you could trim off a few of the leaves. This will help it put energy into growing more roots. Put it in the shade or filtered light until it gets some roots going. You might want to find a few rocks to help secure the stem or use some other device in the pot if it seems a little tippy/unstable. If you get a late freeze move it somewhere like a shed or garage for the night while it is still little.

If you want to put it in the ground later, they are grown in my area which is 9a in the ground. They are root hardy to zone 8 and seem to freeze back here to return in the spring.
I get a little better color on mine in filtered sun or morning sun but I have seen them grown in full sun around town without any problems. They seem to be tough plants as far as gingers go.
I almost never see them flowering around here probably due to them getting froze back in the winter. They flower on the olderer growth. I have been keeping a few in the gh in large pots to see if I can get some flowering this year.