My Little Gem Magnolia Tree Is Losing Leaves

Healthy magnolia blossoms.

Little Gem, a cultivar of southern magnolia (Magnolia grandiflora) is a tree native to the United States. The loss of leaves from a Little Gem magnolia could indicate the presence of disease or need for a change in tree care.

Identification

Little Gem magnolias, which reach up to 20 feet in height and grow best in U.S. Department of Agriculture plant hardiness zones 7 through 9, require full to partial sunlight. If a tree is not getting enough sunlight, its leaves may fall off. Magnolia trees are drought-tolerant, so lack of water is not a likely cause of leaf drop.

Disease

Magnolia trees are susceptible to leaf spot disease, which is caused by a parasitic alga. Leaf spot begins as a round and fuzzy colony on the leaf's surface, but the spots turn gray and the leaves die and fall off.

Prevention/Solution

Leaf spot most often affects weak magnolia trees, so trees that are properly watered and fertilized will be less susceptible. The application of a copper hydroxide fungicide every two weeks during wet and cool weather may prevent the disease.

References

• University of Florida IFAS Extension; Magnolia grandiflora 'Little Gem': 'Little Gem' Southern Magnolia; E. Gilman and D. Watson
• MSUCares: Algal Leaf Spot of Southern Magnolia
• Floridata: Magnolia grandiflora