I think it would be possible to use the cans if the can were the bottom part of the container. Make holes in the bottom of the can for drainage and then fill with potting mix and water. Then after planting the seeds cover the can with something like a plastic bag that has air holes in it. Something loose so that the seedlings would have room to sprout under the bag. Use a big zip lock and tape it around to fasten it on the can. You might need to put some kind of support under it. It does seem like a lot of trouble to go through but I think it would work!
Joann

They would probably work but I still think that milk jugs work the best. I tried several different types of containers last year and this year it's going to be nothing but milk jugs or very similar containers.

Strouper

How big are they? 26 years ago when I bought formula the cans were only about 3 inches in diameter? But if you use 3 cans a week for twins I assume yours are bigger, concentrated, and that you dilute it.

I've never used aluminum. It wouldn't matter much in winter but I'd think come spring they would freeze pretty fast and also heat a lot in warm temperatures. That's just a guess though. I'm not sure where you live but I'm also in zone 6, southwest Ohio, and our temps fluctuate an awful lot in spring.

Like Strouper I prefer milk jugs, gallons over half gallons, over any other type of container I've tried.

Karen

Hi Monica,
I'm thinking if you only use them one season, it might be ok. Punch lots of holes in the bottoms and sides...
I'd be more worried about rust and heat retention, and not use them for edibles.
I'd place them close together in a kiddie pool (also holes for draining) with a plastic cover or shelving unit with a plastic covering or something.
Just be careful of the sharp edges, I'm too accident prone as it is, I'm safer with jugs. :)