My Silver Maple Tree Is Turning Yellow

The silver maple emits sap for syrup.

Often planted as an ornamental tree, the silver maple, Acer saccharinum, is also referred to as soft maple, river maple, silverleaf maple, swamp maple, water maple and white maple, reports the United States Forest Service.

Tar Spot

A silver maple tree that is turning yellow could be under attack from the fungal disease known as tar spot. This is the result of two different types of fungi from the rhytisma family, R. americanum and R. punctatum. The condition initially produces large, yellow spots that eventually turn black.

Effects

The fungi overwinter with yellow spotting occurring in the spring, before giving way to black spotting in mid-to-late summer. The disease primarily affects the appearance of the silver maple leaves and rarely poses any long-term threat. The Maine Forest Service advises that management or control of tar spot is rarely required.

Iron Chlorosis

Iron chlorosis regularly affects the leaves of a silver maple, turning them yellow. It is not brought on by a fungus, but rather by a lack of iron in plant tissue -- stemming from iron deficiency in the surrounding soil, according to Oklahoma Forestry Services. The condition is most common in high-alkaline soils.

References

• University of Nebraska-Lincoln: Tar Spot of Maple
• Maine Forest Service: Tar Leaf Spot of Norway Maple
• Oklahoma Forestry Services: Why Do My Trees Have Yellow Leaves
• United States Forest Service: Silver Maple