These are my walking onions. They were grown from full-sized bulbs, and are now waist-high, quite a bit bigger than last year, and dwarf the row of good-sized Purple Wight garlic next to them. I've found a US website (http://alanbishop.proboards.com/index.cgi?) which has someone who knows a bit about this stuff, so I'm hoping to find out what sort I have. Apparently there are several types.