Question
QUESTION: Hi Jim,
I live in Northeast Wisconsin.  I have a row of blue and white spruce along my driveway.  They are approximately 25-30 years old and in very good shape.  They are branching out into the driveway and I would like to trim them just enough so cars, snowplow etc. don't hit them.  How do cut them back without harming the trees?  Do you cut back one years growth?  I would do it now being it's winter. Is that the right time?  Thanks, Bill

ANSWER: Pruning of evergreens should be done in the late winter or early spring-now is about the right time.

Remove any diseased branches. Unusual colors, bumps or other raised areas on a branch are most likely signs of disease. Cut these branches all the way back to the trunk.

Prune branches that no longer have any needles on them. These branches are most likely dead. Cut them back to the main trunk. Leave branches with brown needles on the tree, as they may still put out new growth.

Evaluate the shape of the tree carefully before removing the bottom branches. If you live in an area with a lot of snowfall, removing the bottom branches could be detrimental to the tree. The snow-filled branches of spruce trees are supported by the branches beneath them. If you remove the bottom branches, the tree's lower branches may break off and die under the weight of the snow.

Trim the ends of the branches back to a live lateral branch to reduce the size of your spruce tree. Do not leave stubs; no new growth will emerge from them. Maintain the tree's general shape and trim sparingly.


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QUESTION: Ok Jim.  One more question.  What is a live lateral branch?  Thanks, Bill

Answer
A branch that grows out from the trunk and is still alive. if you trim off some of the end of the branch and leave green needles the branch will continue to grow but if the branch is pruned back to where there are no green needles left the branch will die. All dead lateral branches should be pruned back to the main trunk.