But then they needed pots.
I found a retro ice bucket at an op shop that had a plastic insert with drainage (if that makes sense), so it was plant ready.
And a lovely floral tin bucket at Spotlight for $5 that has become home to another of the indoor plants. Spotlight also had wire hanging baskets down to $4, so there was another fern taken care of.
If the object you choose as a pot is ceramic or glass and needs drainage holes, you need to make sure you use a specific glass/ceramic drill bit so you don't smash your pot-to-be drilling holes in it.
Here's some other ideas:
Old metal watering cans
tin buckets
glass bowls
toolboxes
utensil canisters
old toys, like a metal dump truck that you can plant in the back of
metal urns or creamers
tea pots (they need to be big to manage most indoor plants though)
enamelware pots
coffee tins
fish bowls
Let us know if you have any creative ideas for upcycling objects into pots.