Quince fruit trees (Cydonia oblonga) grow in U.S. Department of Agriculture plant hardiness zones 5 through 9. They are grown for their showy pink or white spring flowers and large fruits known as pomes, which is round like apples or oblong like pears, depending on the quince cultivar. The ripe, fragrant pomes are generally cooked in sauces, pies and preserves. After establishing the basic frame, older quince trees require only light trimming to keep the branches open. Quince can be pruned from late fall through winter in the dormant period before new growth appears on the branches.
Disinfect the blades of all your pruning tools using isopropyl rubbing alcohol. Use bypass pruners for smaller branches, lopping shears for medium branches, a pruning saw for large branches and pole pruners to access the bigger branches.
Pull off all suckers that grow from the base of the plant or in branch crotches within the canopy.
Remove any dead or broken branches back to the nearest healthy branch, making the cut just outside the protective ring of tissue that connects the two branches, called the branch collar. Cutting through the branch collar opens the plant to infection, which could kill the entire tree.
Eliminate any rubbing or crossing branches to start the plant to enhance air circulation and sun. Depending on the harshness of the crossing, you might need to prune the entire branch back to its point of origin or simply trim the tip just above a leaf node.
Cut the ends of long, stray branches back to just above a leaf node to keep a rounded form from the canopy.
Cut the top of the tree back to about 5 feet tall to keep up the compact size of the quince. If the tree is severely overgrown, you might need to decrease the height in stages, removing no more than one-third of the whole length of individual branches annually until the desired height is reached.