I wouldn't use them. The metal in the cans will rust very quickly. Whether the rust will or will not create a problem with the soil or will affect seed germination, I don't know.

What I do know though, is that hubby left an empty metal coffee can outside this past winter. He had been using it to hold some nails he was using outside in Nov.
Anyways, but mid Dec. it had some snow in it and the top part of the can was all rusted and crumbling. By spring the metal in the can had started to crumble.

I suggest you stick with the "tried and true" containers of recycled plastic containers, gallon jugs, etc.

Fran

Oh and welcome to the WS forum and don't mind all "us crazy people". We are addicted to WS but we love "newbies" and all the questions and helping out those that are new.

We are the friendliest forum on GW.

Fran

I use a lot of coffee cans, nut cans, etc. (3-pound size) and like them for holding toilet paper rolls and newspaper pots. I have also sown seeds directly into them. I always get good germination and they give a lot of headroom, which I like. They do rust, but that doesn't bother me, and I'm on my third year for some. I also sow in soup cans and reuse those, too. After plant out, I store them inside.

As for the lids, I cut out the inner circle about 1/2 inch from the rim, cover the can with plastic (cereal bags are my favorite) put the rim back on, and punch holes in the plastic.

Thank you both for your responses. I did a little web surfing and think I'll try it on some non priority seeds this winter. Thanks again.