Please choose the correct ending to complete the given sentence: Home and Garden: [header] How to prune old apple trees [title] Make sure that the tree is healthy. [step] Pruning an old apple tree can encourage it to develop new growth and fruit. If the tree is brittle, dead, or diseased, then pruning it won't help.

Ending1: Mature trees should be pruned at least twice a year. Older trees should be pruned every two years. Ending2: To minimize damage to the tree as you prune, it's a good idea to prune it at least once a month, or every couple of years. Only prune overly old or brittle apple trees, as these types of trees usually suffer damage from harsh pruners. Ending3: Pruning a healthy older apple tree may end up splitting the tree down the middle. [substeps] Clean the tree and inspect the tips for split or damage, which is a disease that most trees have. Ending4: To determine whether or not your tree is worth saving, look for the following : [substeps] Grayish or crinkled branches: these branches are dead or diseased. If more than half of the tree's branches appear like this, then the tree is not worth saving.

Answer format: ending1/ending2/ending3/ending4