The mulberry tree (Morus spp.) comes in white, black and red; fruitless varieties also exist. These trees vary greatly in height: red mulberries can grow up to 70 feet in height, while black ones top out at 30 feet. Gardeners who grow mulberry trees should prune them annually to keep the tree healthy and neat. Since mulberries weep when pruned, the best time to prune them is during the dormant season, in late winter or early spring. Wait until frost danger has passed for your area.
Check over the branches of your mulberry, looking for signs of dead, diseased or damaged branches. Diseased and damaged growth shows wounds, marring, discoloration or blotches; dead growth doesn't move in the wind and feels brittle. This wood needs to be removed for the overall health of your mulberry tree.
Prepare a 1:10 solution of bleach to water in a bucket. Place your pruning tools in the bucket. Cut off all the dead and unhealthy wood using your pruners; dip the tools back in the bucket to disinfect them in between each cut. Snip the wood off at its base without cutting into the trunk, or cut back to a healthy crotch intersection. Use anvil pruners for cuts smaller than 3/4 inch in diameter and lopping shears for larger one.
Strip any suckers off the trunk of your mulberry, since they suck energy from the tree. Also check for suckers in past pruning cuts and remove them there.
Trim back side branches on your mulberry tree so they have six leaves. This promotes branching, which leads to more mulberries on your tree.
Thin out the tree canopy by removing wood that grows directly upward and wood that grows downward. By thinning out you're increasing air circulation, which helps keep the tree healthy.