Question
We own a beautiful Blue Spruce that is needing to have the mounded area cut down as much as possible. It is about 16 yrs old, about 16' tall. Want to cut about 1-2 foot away (if possible)from the root system and not harm the tree. This sits in our rock garden 3-4 away from foundation. This 2-3 hump is causing water to flow toward the house. hoping by cutting it down it will help to not have as much water just sitting on our foundation area.
Thank YOU!

Answer
The root system is in the first two feet of soil so removing the first two feet of soil from around the tree will kill it. 3-4 feet from the house is too close for a tree this size (this tree can have a branch spread of 26 feet when mature). I would go ahead and transplant the tree to another location at least 16 feet from the house.

Evergreens should be moved earlier in the fall than deciduous plants so they have time to form new roots. They need at least 6 weeks before the ground freezes. In the spring, Evergreens can be planted up to 4 weeks after deciduous trees have opened their leaves, providing that the newly planted trees receive adequate water.

Digging the root ball:

When you want to dig up a tree or shrub for transplanting, retain as much of the root system as possible. All ages of evergreens, can be successfully moved only if a ball of soil is left around the roots. The exposed roots should be protected with moist burlap or newspaper or with polyethylene sheeting. Every effort should be made to reduce root exposure to wind and sun, keeping the ball as moist as possible. It's best to prepare the hole before digging up the tree you wish to move.

Size of the root ball and size of the hole:

For deciduous trees and shrubs the soil ball should be:

Width = 9-12 in. in diameter/every 1 in. of tree diameter
Depth = 6 in./every 1 in. of tree diameter

For example: A tree trunk 2 inches wide would need a soil ball of 18-24 inches wide and 12 inches deep.

Dig the new hole twice the size of the rootball and as deep and fill with good top soil or potting soil. Mulch around the tree with not more than 3 inches deep of organic mulch not piled up on the trunk (pine straw is good). Water with 1 inch of water--place a pan under the tree and turn the sprinkler on and when the pan has 1 inch of water in it stop--do this every three days for the first couple of month then once a week.