A special type of dwarf tree, the columnar apple tree resembles a pole of apples. These trees can be planted in containers or in garden beds and are ideal for areas too small to support full-sized trees. While columnar apple trees need less pruning than full-size or other dwarf apple trees, they do need regular thinning when the fruits sets as well as light shaping and pruning for plant health. Prune columnar apple trees in the late fall or in the early spring, when frost danger passes. Thin the tree when the fruit develops over the spring and summer months.
Clip off dead twigs, which feel brittle. Trim back unhealthy or dead growth to a healthy part of the branch. Discard all unhealthy wood in a garbage bin.
Trim back your columnar apple tree to your desired height. The trees can reach 10 feet tall, according to Apples Fruit. If you let your tree mature to its full height, you will need to stake the tree as the fruit ripens. Apples also taste better when the tree is not producing many apples.
Thin the fruit once it sets to prevent branches from breaking under the weight. Clip off fruit from crowded areas or if the branch looks too weak to support the weight of a mature apple. Thin out fruit where too many apples are growing, leaving one apple per cluster. Clip the fruit off with anvil pruners to thin it.