Hi, My white pine is showing what seems to be a fungal infection. First bark only on one branch turned white, but after a year multiple branches are white. I am very worried, since it is a beautiful and very big pine, and it would be very difficult to reach these branches. I live in North York.
Please, let me know how to treat this. Thank you very much.
Thank you for contacting the Toronto Master Gardeners regarding your white pine tree (Pinus strobus). The most common, worrisome condition in white pines that causes white appearance of the bark is White Pine Blister Rust (WPBR). In this disease, cankers in the bark release resin that can turn white. Pines with WPBR typically have other symptoms such as brown/yellow needles and a second host species is needed for the fungus to complete its life cycle. This Ontario provincial website provides a good overview of WPBR White Pine Blister Rust.
It is also possible that light coloured lichen is growing on the tree branches or some other process that is not harmful to your tree at all. A more definitive diagnosis is difficult without clear photos of your tree and the white branches you are describing. You are welcome to resubmit your question with photos anytime.
Finally, your tree is large and you may decide to have an arborist examine it – especially if areas of concern are hard to reach. Landscape Ontario is a good place to find a certified arborist near you Landscape Ontario
Best of luck with your white pine tree.
June 3, 2022