i've grown scallions successfully in an 8 inch deep window box. now, i have planted some copra sweet onions this year (which are larger onions) in the square foot beds - if it starts looking like it isn't deep enough (8") i'll add additional soil. I epect you'd be successful growing a small amount in a five gallon bucket - it just won't be very many.

Thanks jaclyn6bva!Containers are a new facet of gardening for me & although I've done my research, I still like to hear from experienced growers. I think I've located some inexpensive opaque, plastic storage bins that are 12"D x 18"W x 24"L. I'll drill some holes in the bottom, add some landscape fabric, & 10" of soil...........

I grow onions in containers all the time they do great. Depth is not a problem 8" is fine. I plant mine 2" apart in rows 2" a part. When they are big enouph I pull every other one and use as green onions. The ones left in the container are then 4" apart so they have room to mature.

Cool mikewrt! I was wondering how many onions I would have room for. This gives me a little insight.