Q.Leylandii
Hi I have noticed some strage discoleration on the main truck of 3 of my leylandii. Is this canker? What can i do ? Please advice. Thanks

Certified GKH Gardening Expert
I'm not really seeing anything out of the ordinary for these short lived trees. I can't see the rest of the tree to check for any other signs of damage, but it looks fine to me.
Just be aware that after about 20 years, these trees will, seemingly, die suddenly as they reach the end of their lifespan.
Here is an article for more information on the tree:
https://www.gardeningknowhow.com/ornamental/trees/leyland-cypress/growing-leyland-cypress-trees.htm