Become familiar with the wonderful world of wholesale!! You will probably need a business license and tax ID number to order but this is only one of hundreds of US suppliers of nursery supplies you can access online.

ps. start visiting trade shows - a great way to make contacts and to get some good deals!! Vendors are always ready to cut a deal to snag a new customer.

Here is a link that might be useful: online nursery supply

where are you located?

A M Leonard is good one

BFG SUPPLY is who I use for containers for growing and nursery stock.