Answer: You can trim up your Yew, but you may want to do it over a 2-3 year period. Plants don't respond well to severe pruning all at once so plan on removing no more than one-third of the live material in any one pruning session. Start by removing the branches on the lower third of the trunk. Check the plant all summer long; you may discover new sprouts along the trunk. If so, simply rub them out. Next spring remove the branches from the next third. By the end of the third spring you should have a tree form and as long as you rub out any growth that begins to appear along the trunk, you'll end up with a tree formed Yew. It will take a few years for the bark to harden, at which time no new sprouts will appear along the trunk.
Best wishes with your Yew.
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