Southern Magnolia Tree Problems

The southern magnolia is one of the true southern belles.

With its lustrous, shiny green leaves and abundantly fragrant white blooms, the southern magnolia tree is one of the treasured symbols of the south. Though relatively problem free, there are some pests and diseases that afflict the southern magnolia.

Insects

You might think that any plant with blooms as fragrant as the southern magnolia would be overrun by insect infestations, but the truth is that the southern magnolia is relatively pest-free. The exceptions are slugs that attack juvenile magnolias, plus magnolia scale and the Japanese beetle.

Fungi

Southern magnolia trees are somewhat susceptible to different forms of fungus, such as powdery mildew, leaf spots and sooty mold. Powdery mildew has the appearance of dust on the leaves of the plant, and though not aesthetically pleasing, does not pose a serious threat to the health of a southern magnolia tree. Sooty mold is a form of black, furry-looking mold that can attack a tree that is also suffering from an infestation of magnolia scale. The insects excrete a liquid called honeydew, which is a perfect breeding ground for sooty mold.

Frost

Although southern magnolia trees can survive an occasional frost, the trees do not particularly enjoy temperatures that drop below 0 degrees Fahrenheit on a regular basis. Southern magnolias are typically successful in U.S. Department of Agriculture plant hardiness zones 7 through 9, as these regions tend to offer more frost-free days. Over the course of an unusually cold winter, the southern magnolia can be damaged if the temperature drops below 0.

References

• Cornell University: Sooty Mold
• The Online Gardener: Southern Magnolia
• University of Florida IFAS Extension: Magnolia Grandiflora: Southern Magnolia