yes,wind was bad here in pa. when they bro.you brought up a good point. i used rope to hold the 3 cluster apart staked in the ground.do you think that caused the trees to be stiff and not swing in wind? but i removed that rope 4 months before this happened.others i did not have them secured to stakes.the main leaders bro off about 2 ft above where i had them held.also,do you think maybe inside limbs rubbed on the main stems of each other?can that cause a weakness.i was going to trim every limb that was or could touch in wind inside but i read that you should not prune to much when young tree.i trimed the main stems off those 2 and left a branch limb to act as leader on each.these cluster birch are out in high wind area at my home.when the main stems bro off they left a jagged piece up about 1/2 inch on main stem.1 was broken just about 1/2 inch above a branch ,other was bro about 4 inchs above a branch.that one was real high up the stem ,i would say above 6ft high on that one and 4 ft on other.they get lots os sunshine, ground is good, trees looked ok to me other than we had a lot of rain this summer and leaves were yellow early this fall and more green the first year i planted them.
