In California there is nursery call Muranaka in Nipomo. They grow excellent bonsai stock in the ground. They grow material in sand because it drains quickly and it allows oxygen to get to the roots. They propogate seeds in pots and the trees that sprout the best get planted in the ground.

Some species you let bush-out or run, however, you must control the growth so you can get the structure needed. Talk to your local bonsai club for what works in your area.

The key to growing black pines in the ground is to let the top of the tree run while leaving tight branches near the bottom - prune any lateral branches above the bottom branches and leave only the runner.

If you can spread the roots before planting or plant the tree on top of a flat rock this will cause the roots to spread. Caution, depending on the tree, you only want to touch the roots if the tree is dormant.

Dig the tree up after a few years when the tree has met your objectives - only dig when the tree is dormant!

When I figure out how to post a photo, I'll show you Muranaka.

Marcus