What Is Wrong With My Junipers?

Identification

• Junipers are likely to get infected with armillaria root rot caused by the Armillaria mellea fungus. Also referred to as shoestring or oak root disease, the fungus primarily infects the plant's roots.

Damage

• The armillaria fungus infects the cambial tissue of plants, causing death of the main roots and lower trunk area. Initial symptoms include discolored and stunted foliage, accompanied with defoliation. As the disease progresses, branches in the lower canopy start to die. Mushrooms often sprout at the tree's base. The entire juniper plant is gradually killed.

Management

• Armillaris fungus lives in soil for extended periods. Remove all infected plant roots from the soil before any new planting. Use only resistant varieties in soil known to harbor armillaria. The University of California Extension recommends air drying the soil before planting.