I have been thinking about the metal olive tins...I think it is a good idea to use the olive tins as planters for bulbs, and a good way to re-use items which would otherwise become trash. Yes, you will need to use a hammer and a large nail to make some drainage holes in the bottom of the cans.
Do you have any place to get some bubble wrap? Some people line the inside of the metal pots with one or two layers of bubble wrap; this helps to insulate the soil from temperature extremes.
