I just took the tubes off for the season and they seemed to do the job well. one tree maintained a central leader and didn’t have much if any side growth. it reached the top a long time ago and I probably should have taken it off sooner, but never had the time. I placed a mesh bag over the top to prevent deer from munching the leaves. the second tree also maintained a central leader but had less sun in its location so only about 1/2 the growth. I replaced the grow tubes with rings of hardware cloth. hoping any “weak bark” gets some sun exposure and lignifies well before the end of the season.