Diseases of Spartan Juniper Trees

The Spartan juniper tree is a variation of the Juniperus chinensis species. This tree is a fast-growing evergreen that can withstand a wide array of temperature variations and soil conditions, though it will not tolerate wet feet. The Spartan juniper grows in a slender, conical shape with rich green foliage, and can reach heights up to 20 feet, with a 4-to-6 foot spread. Like many evergreens, the Spartan juniper is resistant to many--but not all--diseases.

Phomopsis Blight

Phomopsis blight is a fungal disease that is especially rampant in the juniper species. This fungal disease attacks the foliage of the Spartan juniper. As the disease progresses, it passes through the foliage and onto the stem issue, causing irreversible damage. Young, newly-developed needles are most susceptible to the disease. Infected foliage will first lighten to a pale green, then change to a reddish brown. Severely-infected foliage will turn to an ash gray and die. Phomopsis blight may also cause canker development around the area of infection. The disease is caused by extreme irrigation conditions with long periods of drought followed by periods of standing water. This blight can be controlled with scheduled applications of benomyl and proper pruning of the areas.

Phytophthora Root Rot

Phytophthora root rot is a soil-borne fungal disease. The disease thrives in waterlogged soils with warm soil temperatures. Phytophthora root rot infects the Spartan juniper through its roots system. Infected trees show severe signs of growth stunt and die back. Symptoms usually begin with browning foliage and single dying branches. The progression of the disease will cause browning of the entire tree, loss of vigor and, in some cases, severe defoliation. Severely infected Spartan juniper cannot be saved, and must be removed and properly discarded. The spread of the disease to surrounding trees and plants can be prevented with the use of fungicidal sprays that are designed for root rot prevention. Avoid planting new Spartan junipers in areas in which an infected juniper has been removed.

Cercospora Needle Blight

Cercospora needle blight is a fungal disease that is most detrimental to mature Spartan juniper trees. Infected trees will begin to show symptoms of infection in the late summer as the humidity and rainfall levels increase. The foliage of the tree will begin to brown or redden in color, and will develop hairy fungal spores on its surfaces. Severely infected trees will suffer extreme defoliation, which will begin from the interior of the tree, working its way to the branch tips. The Spartan juniper will take on a scorched appearance. Cercospora needle blight can be prevented with good air circulation throughout and in between trees, along with good drainage and dry foliage. Fungicidal sprays can be effective when applied during the very early stages of the disease. Speak with a horticultural or nursery specialist for assistance.