I love The After Dinner Gardening book - so fun! Our kids always dig seeds out of their fruit and dry them in the kitchen window. We have more stuff coming up now. We actually have a lime tree and a lemon tree that are in the ground outside and made it through winter - both from seed! And a tiny baby loquat that's still only about 6" high. I think another lemon or maybe an orange is growing in one of my potted plants thanks to the 4-year-old. And I know for a fact she stuffed apple seeds in another indoor plant. Last year I found a bizarre looking round red ribbed squash at a South American grocery store. I just planted those seeds around the yard, and I'm really hoping some of them will come up. After Halloween last fall, the kids and I garbage picked the Arboretum for fancy pumpkins from their patch. We got a few strange ones - white, blue, chocolate brown... Those seeds have all sprouted out back and the enormous vines are everywhere. Fun stuff - I love it.

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.

sand ginger is also named as "Kaempferia galanga" and per google images, the roots should look like as attached& plant should like the one show on http://davesgarden.com/guides/pf/go/49145/

First, congratulations, that's a good sized ginger plant you have. It thrived in your environment and care. I've heard that about ginger not usually blooming in the first year as well, but that doesn't match my experience. Mine almost always blooms, and now that I'm living in north Georgia, and I grow all my ginger in containers, and all my ginger is "first year" ginger. Empirically, I think a lack of nutrients and lower water levels stimulate blooming. I apply light fertilizer to my ginger plants every waning moon (just after the full moon), but I don't fertilize at all after the fall equinox. Our weather also usually gets drier in the fall, and I don't water as often as we get rain in the summer. Nearly all of my ginger plants bloom every year. That's my observation, YMMV. When I lived in Florida (Gulf coast, northwestern FL), I had both "in ground" ginger plants and container ginger plants. Second year plants grow to somewhere between 4 and 9 times as much rhizome by weight as first year harvest. However, if it gets too wet and rots in the ground, worst case you lose it all, and "best case" (not really good either), you get a weakened, half rotted plant that doesn't grow or produce as well as a first year plant. Here's my thinking on this. If you save 4 "seed rhizomes" and plant them 18-24 inches apart in that planter next year, tend them the same way you did this year, you'll lock in the bottom of second year production. Save 6 "seed rhizomes" and your in the middle of good second year production. Any rhizome you have left after that is edible now. And you don't have to worry about your "seed rhizomes" rotting in the ground. You can also start those "seed rhizomes" indoors, to get bigger plants/better production when you do move them outdoors. I start mine after the winter solstice, again on the waning moon (much of my growing calendar is set by the moon and sun). I have to use a heat mat and supplemental (white fluorescent) light to get mine started, although I've had some luck with the heat mat and a south facing window. Commercial ginger growers harvest everything every year. I don't know of any commercial growers that leave ginger plants in the ground over winter. Oh, and when I'm selecting which rhizomes to save for "seed" for next year, the ones that bloom and go dormant in the fall are the ones I use for seed. Any plants that don't bloom and stay green through January (or sometimes March) in my well lit, warm "tropical room" are my spring "cooking ginger." That's not an issue for you this year, but next year, if you plant more than one plant, you might face that choice and situation. Also, you might try mixing some turmeric plants in with your ginger next year. Similar growth, similar requirements for weather and soil conditions, and IMO, prettier foliage, or at least some variety in the foliage. Turmeric rhizome ("root") is available from some grocers and "health food" produce sources. Whole Foods in the Atlanta area carries it in their Atlanta stores (formerly Harry's Farmers Market stores).