1. Dig a shallow, broad hole.
It should be three times as wide as it is deep!
2. Locate the tree’s trunk flare.
Do this by loosening the soil at the top of the root ball and finding the first root – that will mark your planting depth. The root flare should be just visible above grade when you plant.
3. Gently place the tree in the planting hole.
Be sure to move it by the root ball or container rather than the trunk.
4. Straighten the tree in the hole.
5. Remove any synthetic burlap or other material.
If your tree is balled and burlapped (b&b), remove as much of this material as possible, including the wire basket that holds the soil intact, so that it does not interfere with the roots.
6. Refill the hole.
Fill gently but firmly with soil from the site—avoid using excessive planting mix or soil not found on the planting site, which may limit the tree’s long-term growth prospects. Use water to remove air pockets and to settle soil around the root ball.
7. Stake the tree, if necessary, but remove no later than one year from planting.
When staking, use two opposing, flexible ties. Ties should be placed on the lower half of the tree and allow trunk movement. Monitor the ties periodically to prevent choking.
8. Mulch the tree.
As indicated here.
9. Provide plenty of water during planting to remove air pockets, and after planting as the tree establishes.