Take the sheath. Really. The buds you want are adventitious buds which will pop independent of the needle buds. Plus the sheaths dry up and look ugly. I used to cut needles, my trees were always inconsistent on needle length. Working with Boon, I have become convinced that pulling is orders of magnitude better- pull both needles at the same time, don't twist, grasp firmly and pull the same direction as the needle is growing.
I'll revive the Yard Pine thread to show how it works. John
http://forum.bonsaitalk.com/f15/jap...pine-18042.html