Q. My juniper has brown spots scattered all over it where the needles have died. What’s wrong with my shrub?
Jeff from Canfield
A. There could be multiple issues. This juniper is actually near your home’s heat pump.
First, it could be winter desiccation. This is where the plant does not take up enough water through the roots to support the foliage above ground. Certain parts of plants are affected, and the foliage dies.
All evergreen shrubs lose water during normal plant functions, even during the winter when other plants are dormant. So you need to water certain evergreens in winter. This is even truer for those close to your house foundation. On late fall and winter days when the temperature is above freezing, watering will benefit your evergreens. A good watering practice is to give them 1 inch of water using a slow, deep watering method.
Next, it could be a fungal disease. Several factors affect junipers specifically. For proper identification, look for tiny black spores on the infected branches, which is a telltale sign.
If it is a fungus, our OSU Extension experts recommend this:
Space new plants to provide good ventilation and air circulation and avoid heavily shaded areas. Avoid wounding plants, especially in spring and autumn.
Amend soil before planting. Plants growing in heavy, poorly drained clay soils are susceptible to other diseases and stressed by constantly wet roots.
Water plants in early morning so the foliage will dry as soon as possible. Maintain adequate fertility, but do not over-fertilize.
Prune out diseased branch tips during dry summer weather and destroy them. Do so only when plants are dry and no rain or overhead irrigation is expected for several days. Avoid excessive pruning or shearing.
Chemical control of tip blight diseases normally is not necessary in established plantings. If you do use a fungicide, be sure it is labeled for use on the plant to which you are applying it. Plus, read and follow all label directions.
For more on juniper diseases and environmental issues (which also relate to other evergreen shrubs), goto: http://go.osu.edu/evergreenshrub and http://go.osu.edu/winterinjury
Eric Barrett, OSU Extension Educator, Agriculture & Natural Resources, Mahoning County.