Hi John, my hunch is that it’s old, too. I’ve some old stuff, but have watered it down some and stored it in a cool location. But I’ve not used it for myself lately, and ended up just dabbing the scion tips with it at the propagation fair (I never coat the bands, they break down as designed that way).

I suspect the Doc they’d sold you had likely sat around somewhere for a long time. Is there a date of manufacture or expirationon on it? In the past, when top-working my own trees, I’d always coat a union twice, giving the first coat plenty of time to dry before the second, but don't recal any cracking. I’ve actually gone through several containers of Doc Farwell, too, but never noticed it cracking toward the end…