I used to get mailings from a Southern company called "Bonsai by the Monastery" or something like that. If I recall, they had some large bonsai pots to might fit your needs.

How are you going to root prune those trees once they become big and heavy?

Well i cant really say from experience since most of my trees are small and i havent done it yet.

But a good book for reference is 'Japanese Maples' by Vertrees. He mentions that acer palamtums are suited well for containers. They can be keep at certain sizes with some judicious pruning. Root pruning was one of the reasons i am looking for wider rimmed pots. Ones that would be easier to pull out the tree ti get at the roots. Most japanese maples arent to vigourous of a tree, and alot of my cultivars are dissectums which dont grow to big quickly and dwarfs which naturally stay fairly small.

Mike

A small pot means you have to water almost every day.

Brussels Bonsai has inexpensive glazed pots for your size trees, but shipping cost will probably be painful. I have 3 or 4 potted trees displayed on rocks in the garden. They are watered every other day by overspray from the garden system. If the moss on the surface of the pot soil starts to look dry, I give them a good soaking. It has worked so far, even in 100f weather.

I live in the country and use "bulb" pots I get at the local farmers co-op. They come in all sizes and are inexpensive. The ones my co-op carries come from italy and look really nice with a small tree in them. Zack

get inexpensive plastic bonsai that come complete with plates which you can weigh down with rocks to keep the wind from tipping them over.