A nursery basket is the frame you use when you dig shubbery with a root ball (balled and burlap). They come in different sizes. You will want the 26". For the top, you will cut away everything but the top lid. For the bottom cut the top row and fold it down to keep discs in the basket. The only problem is they are normally sold in increments of 25, which is ok if you doing 18, but not so good if you want just one. The baskets are 3-$4.00 each. The big expense is the chain which we buy by the bucket at Lowes.
Chris
I don't have any pics, but it's two nursery baskets with portions cut out to make a top and bottom, connected by 8 outer chains and 4 inner chains via ziplocks. Requires hanging.