Hi Stephanie,
I've painted them with acrylics and I know there are special Krylon paints for plastics. It's also fun to decorate them up with beads and things. I have a post in our Garden Art forum where you can see some.
The thread "My new flowerpot..." in
Garden Art forum
When I make them very ornate, I use them as a cachepot with another pot inside, but I have grown plants directly in pots I've painted. I've never noticed any problem with the plants.
I have to be on the road today, so I won't be back here until late afternoon.
