Flaky Growths (Lichens) on Trees and Shrubs

Don’t panic when you find flaky gray, green, white or yellow substances, known as lichens, on the trunk or branches of your trees and shrubs. These growths do not damage the plant, but may indicate your tree and shrub needs a bit of TLC.

Lichens are composed of a fungus and green or blue-green algae. The algae provides the photosynthesis to produce food, while the fungus supplies water and minerals and protects the algae. This mutually beneficial relationship allows them to withstand harsh environmental conditions.

Although the lichens usually do not harm the plant they reside upon, they are most common in declining trees and shrubs where branches have died, allowing the sunlight to reach the lichens.

Reduce the problem by providing plants with proper care. Expand the mulch beds around trees and shrubs. Remove dead and damaged branches and water plants thoroughly when needed.

A bit more information: Further increase the health of your trees and shrubs by expanding the mulch beds. This will make maintenance easier for you and improve the growing conditions for the plants. Use organic mulches like woodchips and shredded bark that conserve moisture, suppress weeds, reduce competition from grass and improve the soil as they decompose. For more information on lichens, click here.