We planted 22 trees last year in a mixed fruit and nut orchard that we hope to develop into a food forest. Midway through the summer,we got the full effect of the drought. Our well went dry, and our pond dropped too low to draw from. I couldn't get any water to them since Mid July. Three of them looked like goners going into winter. We had a hard freeze in early winter before we had any snow. It now looks like we may have lost 10. A few of these I can't quite tell. The bark has a healthy color and the trunk is flexible, but when I scrape, I can't find the green Cambrian layer. The ones I can't tell are an apple, a hazelnut, an American chestnut, and a plum. These are what the scrapes look like. Should I write them off, or wait?
I'd give it a wait and see for now. If nothing else, your rootstock may have survived and now you get to try out your grafting skills. If enough of the grafted portion survived, you could get new growth from there. I've had it go three ways from grafted trees, new growth on the graft, new growth from the rootstock and completely dead. By mid-May to June you will know what your circumstance is on this.