Well-grown trees and shrubs have been pruned during their production and should be well-branched and typical of their species. Contrary to older instructions, you should not prune a tree or shrub after it is planted. It should have been properly pruned during its production. Choose one whose branching pattern is not wrong for its type. The crown should be symmetrical and balanced.
If the tree is being delivered, have its planting site marked and the tree placed close to the what will be the edge of the hole. Now comes the most important part of all: digging the hole.
No matter what has been said in the past about how to plant a tree, modern research has shown that you must find the root flare and plant the tree or shrub so that the flare is at or just above ground level. If it is planted too deeply, the tree will not thrive. It will decline and ultimately have to be removed - always after the guarantee is up.
So what is root flare? It is the spot where the the trunk widens and roots begin to emerge. If the plant is typical of most in the nursery trade, it may be a few to several inches below the top of the soil ball. Remove the twine and open the burlap on a b&b plant. Probe around with your fingers or something like a screwdriver (gently, please) until you find the first roots. If the flare is not at the soil surface, gently remove soil until it is exposed. Take care with b&b stock not to loosen the ball while you do this. Also when removing a tree from a pot, it is better to use a utility knife to cut the pot from top to bottom on both sides so it can be removed from the root ball instead of the roots from the pot.
After you find the flare, measure the depth hole you will need to place that flare at or just above the soil line. Dig the hole only that deep, but as wide as you can in a shallow bowl-shaped configuration, the wider the better. Carefully place the tree or shrub in the hole. Bend back the wire basket often present on b&b trees, but don't try to remove it. Likewise, cut away all the burlap you can without loosening the ball. Don't try to remove it all. Back fill about half way with the soil that came out of the hole. Research has shown that it is better to put the soil amendments into the top third of the hole or as a top dress when the hole has been refilled. Fill the hole with water to settle the soil and remove air pockets. You can use a root stimulator if you like, but don't use fertilizer. Finish filling the hole and pack gently. Mulch your new tree with an organic mulch and keep track of the soil moisture for the entire first growing season. Be sure the tree gets the equivalent of an inch of water a week (one and a half inches in sandy soil) and more should the weather be especially hot, dry and/ or windy. The care you take the first year it lives with you will be repaid many times over in good health and long life for the tree you have chosen.
