Hi Susan,

Thank you for reaching out. It is not recommended that you top a conifer tree. Conifer trees do not respond well to topping, and will result in the loss of apical dominance (the classic single leader growth of conifers). This will allow for the lateral branches to take over and you will end up with multiple leaders that may have weak attachments and structure. Topping also opens the tree to internal decay, disease, or damaging insects.  With these increased risks, the tree may become a hazard not only to itself, but neighboring trees, your property, and potentially people. We recommend contacting a Certified Arborist to come out and consult with you on alternative pruning, or having them remove it if needed.

I've attached a couple resources on why topping is harmful, as well as alternative procedures to topping below:

"Why Topping Hurts":

https://www.treesaregood.org/Portals/0/TreesAreGood_Why%20Topping%20Hurts_0321.pdf

Alternatives to Topping:

https://s3.wp.wsu.edu/uploads/sites/2073/2014/03/092507.pdf

"What Happens to a Tree After it is Topped":

https://www.purdue.edu/fnr/extension/question-is-tree-topping-a-good-method-and-what-happens-to-the-tree-after-it-is-topped/

Please let me know if we can help any further.