My Magnolia Bush Has Brown Leaves

Most magnolia trees should have green leaves.

The magnolia tree blooms in early spring with colorful, soft blooms. Magnolias have stiff leaves that can be green with brown or silver hues. Brown leaves indicate disease or environmental stress.

Types

Some magnolia trees feature leaves that are naturally brown on the underside, while other cultivars have silver or green undersides, especially Southern magnolia cultivars. If your tree has naturally brown leaves, study the color to distinguish changes from the leaf's natural hue.

Potential Causes

Magnolia leaves that change brown may have fungal problems, such as leaf spot diseases. If the magnolia leaves turn brown, shrivel and die, and the trunk has grayish or black rot lesions, the tree has the fungal disease nectria canker. If leaves brown and wilt on part of the tree while other leaves remain healthy, your tree has verticillium wilt. Brown leaves can also indicate a soil imbalance, chlorosis or even cold damage.

Considerations

Since there are many causes of brown leaves, don't take action right away. Watch the tree to determine the cause or get a county extension agent to run soil and leaf tests for disease spores. Trees with leaves that are brown from cold damage, chlorosis or leaf spot can be cured; those with nectria canker or verticillium wilt cannot be cured.

References

• Clemson University Extension: Magnolia; Debbie Shaughnessy; 1999
• Mr. Grow: Frequently Asked Magnolia Questions
• Yardener: Problems of Magnolia
• The Morton Arboretum: Chlorosis