Ancient texts refer to the pomegranate over 2,000 years ago, which makes it older than either peaches or almond trees. Though pomegranate roots may suffer from root rot nematode, their roots typically do not need pruning care. Pruning a pomegranate's roots may be required to move the tree or if a root is interfering with a water line, pathway or the foundations of a home.
Prune the roots of a pomegranate one year before moving the tree. Shortening the roots will force the tree to develop new feeder roots in order to cope with its reduced ability to take in nutrients. Once the tree is moved, the new feeder roots will support the tree adequately.
Calculate the size of the root ball you must leave inside the pruning ring by measuring the width of the pomegranate stem with a pair of stem calipers. Multiply the total inches of stem by 18. Your root ball should be this diameter in size. For example, a pomegranate with a 2-inch wide trunk should have a root ball diameter that is 36 inches wide. Dust a circle around your tree using baker's flour to outline the diameter. The pomegranate's stem should be in the center of the circle.
Insert a spade into the ground along one portion of the circle. Angle the spade in toward the tree, and sink it all the way to the end of the blade. The spade will cut the roots as it slants inward.
Work the spade in a circle around the tree, cutting roots as you go. Water the tree so the root ball remains as damp as a wrung out sponge for two weeks until new feeder roots can develop.
Wait one year to dig up the tree. Dig up a root ball that is 8 inches wider in diameter than the circumference that you root prune your tree.
Excavate the soil around the pomegranate tree roots with a mattock or grub hoe. Completely expose the root, including soil beneath it.
Sever roots smaller than 2 inches in diameter using a pair of branch loppers. Remove larger roots with the blade of a mattock.
Remove only the root sections that are troublesome. A pomegranate needs an equal ratio of root mass to canopy to support the tree. Pry the root from the soil with a pry bar or shovel.