when the leaves turn yellow and topple over.then leave them a week or so and lift gently.dry them out i put mine in the sun outside if its nice spread out on a tray,then they will store ok.

Which in the UK is late August early September - no idea in Texas.

In southern Texas, that's likely to be within the next month, Farms here are already harvesting. In northern Texas, the grow a different kind, which doesn't bulb up until after the solstice, like MG's

Fascinating TugB the difference in harvesting times...

True, MG. In hot summer areas, like here and south Texas, the onions that are normal to you would cook in the ground before they finished bulbing up. So instead, we plant short-day onions, which grow over the winter, and start bulbing up at the spring solstice. The hard part is finding seed for short-day onions, since most seedsmen are based in the north, and don't know short-day onions from Adam!

Do they produce t he same size bulb as 'normal' onions TugB? Learning here :-)

Actually, they are often bigger than average, especially the Granex types, such as Texas Grano 502. Maybe because they can spend up to 6 months growing leaves! Unfortunately, they don't store well, so sets are not to be found on the market.