Answer: There is a procedure called bridge grafting that works well for orchard fruit trees, such as apples and pears, but it doesn't work so well with cherry or peach trees. I haven't been able to find anything that states it is effective on ash or other shade trees. It involves taking young twigs and making a bridge across the gap. It's best explained through pictures, and is most effective when you can complete the procedure as soon as possible after the damage has been done. This link will take you to a text document explaining how to do bridge grafting, but I recommend that you try and find a book or maybe an experienced orchardist or tree surgeon who could supply you with a step-by-step, illustrated procedure. I wish you the best of luck!
Bridge Grafting Fruit Trees
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