You usually don't harvest onions until the tops start to die back. The bulbs will swell up only in the very last part of growth. The tops start to turn yellow and I usually wait until most of the outer leaves are brown, then knock over all the tops. Another few days, and then I will dig and put in a shady, dry, place to cure - for me I put them in my garage or even my basement (if the garage is too hot). You just dug them much too soon to get decent onions.

I just pulled them up an hour ago--can I plant them back in the ground? They've been in the ground since last September, so 7+ months ago. That isn't too long? Thanks!

Do you know what variety of onions they are? I assume you are somewhere in the south where short day onions can be grown thru the winter. I believe mid/late April is usually when the growers in Georgia harvest the short day Vidalia onions but then I purchased some at the grocer this past weekend so it maybe earlier. If these were not a short day type then that may be why they had not bulbed up yet. They do look like they might have just started to bulb before you pulled them.

I don't think you will have any luck with putting them back in the ground but it wouldn't hurt to try I guess. When onions bulb, about 2/3 of the bulb is visible above ground as long as they were planted at the correct 1" depth so it is easy to determine how far along they are. Drmbear gave you good information on how to tell when they are ready to harvest.

Tough lesson to learn but gardening is a never ending lesson!

Thanks! The roots were all still intact because they were so shallow, so I snipped the tops and re-planted them. Hoping for the best! They're Red Burgundy onions. I live in California where it doesn't really get cold until November or December, so I'll try planting them much later in the year.

Bulbing of onions is dependent on day length. The onions know when to bulb based on the length of daylight. The amount of daylight that triggers a onion to bulb depends on whether they are short day like your Red Burgundy 12-13 hours, Intermediate day 13-14 hours, or long day 14-15+ hours roughly. These daylight ranges are when they are triggered to BEGIN to bulb. Like drmbear said you harvest when most of the leaves have turned and fallen over. Just be patient.

Good luck with the re-planting. I hope it works out! Please do let us know the results.