Some gingers, especially some Hedychiums naturally grow that way, but if it's due to lack of room they'll also do that, they do it in pots alot. You definitely can go ahead and divide them, Where in zone 9 are you? You can either go ahead and do it now or wait until next spring when the new shoots begin sprouting, it's a little easier then because you cut off any old pseudostems from the year before so you don't have to stake anything. Gingers are very shallow rooted, most grow in the top 3 inches of soil, no deeper. I would say on avaerage we plant ours 2 to 3 inches deep. Water them in , fertilize and cover with mulch, like oak leaves, pine needles, etc... then you're good to go :)
Liz

Thanks, Liz...we're in San Diego. They've gotten so crowded I think I'll wait till spring and do a lot of culling back. I also think I need to plant them away from afternoon sun...

they don't like that afternoon sun. We grow only 3 gingers that we grow in full sun, most really prefer shade in the afternoon. you are quite welcome. Is your zone similar to mine? I guess your humidity is different from ours here? I lived in Sacramento area for a short time and it seemed very similar to Florida but, I realize all parts of the state aren't the same (people always think of the entire state of Florida as the same).
Liz