Hello Ruth,

There are many reasons for the needles on white pine (Pinus strobus) to go brown, including disease, insects and environmental agents. Read here to learn more. https://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/visual-guides/eastern-white-pine-problems.aspx

More than likely, your white pines are going through a cycle that evergreens go through when they shed the interior needles. New growth on an evergreen takes place at the tips of the branch. Although we think that needles of evergreens are permanent, the interior needles die and are shed leaving the new growth at the tip of the branch. This is a natural progression and does not mean that there is something wrong with the tree. Read the attached article for more information.

https://www.canr.msu.edu/news/why_are_my_evergreens_losing_their_needlesAs I said in my comments, you should obtain a correct diagnosis by contacting Plant and Pest Diagnostics Lab at MSU Extension: https://www.canr.msu.edu/pestid/

Or contact a certified arborist—you can find one in your area at www.treesaregood.org. the website of the International Society of Arboriculture.

Thank you for contacting Ask Extension.