How to Trim Blue Spruce Trees

Colorado spruce (Picea pungens) is commonly called blue spruce for the pale-blue cast of its needles. Blue spruce provides winter interest as well as shelter for birds and animals. It grows slowly, eventually reaching a mature height of 60 feet or more. Like most conifers, it needs little to no pruning for maintenance. Because blue spruce branches all the way to the ground, you may want to remove a few branches for clearance if the tree is planted near a window, or is blocking a driveway or sidewalk.

Canvas gloves

Safety glasses (optional)

Long-handled pruning shears

Yard waste bags (optional)

Clean pruning shear blades before each use. Dip them in boiling water for 30 seconds to kill bacteria, fungus and insect eggs. If you don't want to wait for water to boil, a cloth dipped in rubbing alcohol will do the trick.

Estimate the height of the blue spruce and divide the number by three. That's how far up from the ground you can remove branches.

Put on canvas gloves and long sleeves to protect yourself from sap and sharp needles. Wear safety glasses if the spruce's branches are longer than your arm.

Prune out the lower branches, starting with the lowest and working up. Set the blades of your pruning shears at a 45-degree angle, cutting down and away from the trunk. Leave 1/2-inch, angled stubs that will drain moisture and heal fast.

Cut up the pruned branches and dispose of them in yard waste bags or put them in the compost pile. Clean the blades of pruning tools before storing or using them on other trees.

Prune conifers any time of year, but winter pruning causes less injury and there are fewer active pests and diseases to infect pruning wounds.

Never cut off the top of a blue spruce unless you want to kill it. Very few trees can tolerate "topping."