How Often Should Fruitless Mulberry Trees Be Pruned?

Pruning helps keep trees healthy.

Trees need pruning for a variety of reasons, from the purely aesthetic trimming for height or shape to the lifesaving pruning that cuts away disease and damage. Fruitless mulberries often "bleed" after pruning. This is not harmful, but it is avoidable if you prune the tree at the proper time. Selective pruning helps promote new, strong growth as well. The secret is knowing when to prune the tree.

Pruning for Size

The old cliché, "out with the old, in with the new," applies in reverse to fruitless mulberry trees. To keep the tree small, prune away new growth every year or two. Leave the bumps, or knuckles, where the young branches attach to the tree to avoid injuring the mulberry. Do this during the dormant season, generally between the time fruitless mulberries drop their leaves in the fall and develop new buds in the spring.

Pruning for Health

Scale insects and mites sometimes infest mulberry trees, causing damage to the foliage. Some diseases, such as leaf spot, powdery mildew and bacterial blight, may also attack the tree. Treatment of infestation and infection usually includes cutting away infested or diseased areas of the tree. Do this type of pruning as soon as possible, regardless of season. Most infestations and diseases occur in spring or summer. Cut away dead, dying or infected areas as much as possible. Although a hard spray of water can knock mites and scale insects off the tree, insect waste left behind can become a spore factory for sooty mold. Inspect the tree to be sure infested areas do not develop fungal infections.

Pruning for Strength and Beauty

When the mulberry tree's branches become tangled or too dense, interfering with leaf production and proper air circulation in the canopy, prune the tree. Like regular pruning chores, this type of pruning is best done during the dormant period. Trimming away excess branches allows the tree to spend more energy supporting its remaining branches. Eliminate weak or distorted branches and thin out dense areas where sunlight and air circulation are poor. Choose one or two sturdy, low branches and cut off any branches below them. Cut away suckers -- baby trees growing from the base of the mulberry. If any limbs appear to be competing with the leader (trunk), cut it off to keep the tree from developing multiple trunks.

Pruning for Safety

Lower limbs on fruitless mulberry trees are only a problem if the trees are near driveways, streets and walkways. In these areas, low-growing limbs and foliage may interfere with a driver's ability to see or become a hazard or barrier to people trying to walk under the tree. Prune away lower limbs whenever necessary to eliminate the problem. The best time for this type of pruning is usually after the foliage is mature, in summer. Lightning strikes, high winds and hail can crack and damage limbs without knocking them off the tree. Cut these off the tree immediately.

Wound Dressings

Generally, pruning cuts made to fruitless mulberry trees require no special care and will heal on their own. If you believe the wound needs a dressing, use a white or other pastel color, watered-down latex paint and apply only a thin coating.

References

• New Mexico State University; "Pruning Fruitless Mulberry"; Curtis W. Smith; January 2001
• New Mexico State University; "Training New Trees"; Curtis W. Smith; August 2005
• Iowa State University Extension; "Pruning Trees -- Shade, Flowering and Conifer"; Jeff Iles, et al.; March 2008
• University of California Cooperative Extension; "Fruitless Mulberry Tree"; Kathie Carter; July 2007
• New Mexico State University; "Sap Dripping from Pruned Mulberry"; Curtis W. Smith; November 2005

Resources

• OklahomaStateUniversityExtension: Putting Down Roots
• UniversityofFloridaIFASExtension; "Morus Alba Fruitless Cultivars"; Edward F. Gilman, et al.; October 1994