Impressive moringa tree

You may have seen this image in the video I posted yesterday:

This moringa tree at H.E.A.R.T. has seen quite a few winters and keeps coming back.

They don't protect it, and as you can see, the trunk has thickened up significantly. It's almost 2' across, though it may be hard to tell from this photo.

My own tree-protecting strategy has kept my moringas from freezing all the way to the ground thus far, but I'll bet there's a point where the trunks will get so thick they become impervious.

Perhaps some experimentation is in order.