I have 4 Sissoo trees which grow about 6 feet a year and are very brittle. Now they are 12 feet tall and have very skinny trucks because they are young and were planted about 3 months ago. Where I live there is lots of wind. So I stake them with 2 stakes apace in a V at about a 10 degree slant, they are sticking 6 feet out of the ground, and then screwed 5 foot extensions to I can tie them off higher so they don't get broken off. I put a cross pole about 5 feet above the ground between the 2 poles about a 6 inches from the top of the big poles.They do shake quite a bit with the wind so my question is the cross pole between the 2 main poles is at the right height are should they be lowered. This is an engineering question and I just don't know.
Richard