gardenmommy...live and learn... I would suggest googleing "harvesting onions" and you will get 276,000 links. Some of these are youtube videos (a picture is worth many words). You may also use the search function at the top of this page. It will give you many links to growing, harvesting and storing onions. There is a whole other forum devoted to "alliums". check that also. Many folks are asking the same questions there. The tops falling over is a sign they are ready to harvest. Good Luck!

I haven't grown onions myself yet, because all the bugs eat them before they can do anything... but from what I've read, you harvest them when the tops fall over. After that, you leave it out to dry or you could obviously start eating ones right away that you would use.

Bugs eating onions? I would think that onions would be the very, very last thing to be eaten by bugs. Also you do not have to yank them as soon as one falls over Unless it is extremely wet, they will store fine in the ground for a couple more weeks and increase in size and keeping ability.

Harvesting

Pull green onions anytime after the tops are 6 inches tall. Green onions become stronger in flavor with age and increasing size. They may be used for cooking when they are too strong to eat raw. Though leaves are traditionally discarded, all parts above the roots are edible.

Remove any plants that have formed flower stalks and use immediately. They do not produce good bulbs for dry storage. Harvest in late July or early August, when most of the tops have fallen over. Allow the plants to mature and the tops to fall over naturally. Breaking over the tops early interrupts growth, causing smaller bulbs that do not keep as well in storage.

Pull the mature onions in the morning and allow the bulbs to air dry in the garden until late afternoon. On especially hot, bright, sunny days, the bulb may sunburn. On days when this is likely, remove onions to a shaded location and allow them to dry thoroughly. Then, before evening dew falls, place them under dry shelter on elevated slats or screens or hang them in small bunches. Tops may be braided or tied with string before hanging. Full air circulation for 2 to 3 weeks is necessary for complete drying and curing. Keep the dry wrapper scales as intact as possible on the bulbs, as they enhance the keeping ability.

After the bulbs dry, cut the tops 1 _ to 2 inches long (at or above the narrow spot where the stem bent over), and place the bulb in dry storage with good air circulation. Do not try to store bulbs that are bruised, cut or diseased, or those with green tops or thick necks. Store under cool, dry conditions. Dry onions may keep until late winter, but check them regularly and use or discard those that begin to soften or rot.

I too am growing onions this year (Spanish sweet) for the first time. Only 4 this year but more next year! So far so good. They say pull when the tops flop over and get about half dead looking.