The plants do well, but I can't seem to get them to bulb. The time you plant them is supposed to affect whether they bulb or not. See this post on Gardenweb.
http://forums.gardenweb.com/forums/load/allium/msg1021441317478.html

"Permacopia II, an Encyclopedia of More Plants for a Sustainable Hawaii" by D. Hunter Beyer says garlic needs high elevation (3000 feet and above) and the dry side of the island. I've got some in my greenhouse (to keep them dry, I'm on the east side), and they aren't forming heads. I can eat them, but it's like the difference between green onions and yellow--very mild and not very big.