Whire Pine Rust Blister - Ask Extension
I have a white pine with several branches exhibiting the rust blight. Your tip sheet suggests trimming at the branch or cross-section and leave 4 inc...
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Whire Pine Rust Blister #876529
Asked July 09, 2024, 3:21 PM EDT
I have a white pine with several branches exhibiting the rust blight. Your tip sheet suggests trimming at the branch or cross-section and leave 4 inches of live material -- would that include 4 inches from the main trunk, essentially leaving nothing?
Also, I assume it is necessary to trim now and not wait for cold weather?
Crow Wing County Minnesota
Expert Response
Hi David,
What they mean is that when you cut infected branches off, the pruned branch should be cut at least four inches down from any rust infection. It's a precaution to make sure you're cutting out all the infected wood, even if it isn't visible.
If most of a branch is infected, prune the branch off at the trunk.
Here's the U's fact sheet:
https://extension.umn.edu/plant-diseases/white-pine-blister-rust
The DNR says pines can be pruned any time of year. Do so on a dry day.
https://files.dnr.state.mn.us/forestry/ecssilviculture/tipsheets/tipsheet_10.pdf
Good luck.