The enormous Mullberry in my front yard was here long before I was. It was split on my arrival about 2 years ago. The split is deep, from the branches to about 8 inches from the ground. It has probably been this way for some time. I trim the branches to try and keep it from falling.

Is there anything else I can do? I exposed the roots two years ago.

I hate to tell you, but furitless mulberry trees are on my 'use only as shredded hard-wood mulch or firewood' list. They are weak-wooded, have invasive surface roots, and are just not great trees. Unless you have a serious sentimental attatchment to this particular tree, I'd write it off. IF you absolutely want to prolong this tree, clean the split out, hit it with some hydrogen peroxide, and give it a bit of tree trunk goop to start, After that, just try to keep it clean of debris and standing water.

I don't like it either. But it is what I have to work with. This split has been this way for some time now. Should I try the H2O2? If so what concentration?

I have pruned off some serious limbs without using any goop in the past. I've been lucky. My neighbor battles boring insects on every cut.

I'll try this stuff and try to keep it alive. But, I'll keep stuff out of it's way and I won't cry when it falls.

You might want to be ready to plant a new, better adapted tree to replace it, that way you have a solution handy.

As far as the H2O2, use it straight. Kills the ick, infuses teh area with O2 and that lets the aerobic (good) microbes flourish.