Question
I live in Minnesota and have a tree, I am not sure the species, that has acquired a leak in one of its upper limbs. Also, after cutting a lower small branch, the clear liquid started pouring from there as well. I am sure it has to do with the recent spring thaw and the large amount of water in the ground. My concern is for the health of the tree. Will the constant contact with water damage the tree? How long should I expect the leaking to continue? At what point should I have someone come look at it? Thank you.

Answer
Several tree species will leak if pruned especially in the spring. The worst is River Birch. This is normal. River birch transpire a great amount of water-this is especially true in the spring when the pressure is higher to push the sap from the roots to the new leaves. Normally you see this after branches have been pruned in the spring or maybe broken off. It can happen with no wounding of the branches. I would not be concerned it will lessen as the warmer months come. Nothing really needs to be done.
Trees absorb water through the root system and through pressure the water is transported to the foliage. the growing action of the cells in the leaves cause the pressure drawing the water and food up to the leaves where it is turned into food for the tree.When a branch is pruned this wound is an outlet for the sap. It will stop on its own as the wound heals and not harm the tree.