Hello,

Eastern white pine (Pinus strobus) is susceptible to many diseases, insects and environmental agents. A leader dying back could be due to birds perching on it, an attack by the white pine weevil or transplant shock. 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

And here: https://www.canr.msu.edu/news/white_pine_weevil_damage_is_being_seen_now_in_evergreens

So it is difficult to assess what caused the original problem. White pine trees will form a new leader when the first is damaged. Its nature is for the next bud to form a vertical leader which is what happened on your first tree.

You can obtain a more thorough diagnosis and possible treatment by contacting MSU Extension’s Plant and Pest Diagnostics Lab. To learn how to make a submission go to: https://www.canr.msu.edu/pestid/

From the picture, it looks like mulch under the tree may be piled up against the trunk and the crown. This may cause the trunk to rot so it would be wise to pull it 2-3 inches away from the trunk.

Since white pine can develop chlorosis in a high pH soil, a soil test would be beneficial to establish the nutrient level of the soil. To obtain a soil testing kit, go to: https://homesoiltest.msu.edu/get-started

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

I hope this helps you with your trees.

Thank you for contacting Ask Extension.