Cedar-Apple Rust disease is a very common disease that affects cedar trees, junipers, and apple trees. It is unique because, in order to perpetuate itself, it must alternate between an apple tree and a cedar or juniper tree. Therefore, it is important to treat all apple trees, junipers, and cedar trees in an area, regardless of whether they are showing symptoms.

Symptoms: The symptoms of Cedar-Apple Rust are most identifiable on apple trees. In mid to late spring, small pale yellow spots appear on the upper surfaces of the leaves. As the season progresses, the spots grow in size and small black or brown spots develop in the center of the larger yellowish spots. As the spots develop and the tree comes under more stress, leaves and fruit may drop prematurely. Cedar-Apple Rust is common on both fruit-producing apple trees and ornamental flowering apples.

In the spring, fungal spores from the brown and red galls on juniper or red cedar trees are blown by the wind onto the leaves of apple trees, where the spores infect the apple tree and rapidly multiply during wet periods. As the season progresses, fungal spores from the apple tree are blown back onto juniper and red cedar trees, causing a new infection.

Recommended Steps to Control Cedar-Apple Rust:

Cedar-Apple Rust cannot be controlled during the active growing season after it has already infected the tree. However, applying a fungicide spray during the growing season on infected trees, as well as surrounding cedar and juniper trees, can reduce the degree of infection and re-propagation.

• During the growing season, spray all infected and uninfected cedar, juniper, and apple trees with Fungi-Fighter.

• Repeat the spray a second time in about 14 to 21 days.

The following spring, spray the trees (especially apple trees) with Monterey Fungi-Fighter:

1. First spray: when the tree flowers.

2. Second spray: when about 75% of the flower petals have dropped.

3. Third spray: about 10 to 14 days after the second spraying.