To prune an old apple tree, look at the tree from top to bottom. Look for branches that are dead and diseased, and start by cutting those off. Shape the tree so that it has a strong central limb and light and air can reach all parts.
When pruning an old apple tree, wear gloves and use sharp garden tools such as a saw, hand clippers or a pole pruner. Use a ladder to better identify and evaluate problems with taller trees. Old apple trees are best pruned in late winter or early spring while they are still dormant.
Select dead or diseased branches to remove by looking for those that look black or oddly colored or that have wrinkled bark. Remove any limbs that cross or rub against each other or that interfere with the main branch. Cut close to where the branch attaches to the trunk so as to not leave a stub. Do not remove more than one third of an old apple tree at one time.
New branches are stimulated to grow by pruning, which makes an old apple tree more productive. Though te tree may not need any pruning for a few years afterwards, look at it every winter to spot potential problems.