Summer is the time when juniper disease and pest damage symptoms are most obvious.
Or you may have insect damage. These two diseases are fairly easy to tell apart, said Putnam. Infection usually occurs in the spring, when there is abundant moisture due to spring rains, and when the young foliage is expanding. Infection can also occur later in the year if the plants have been pruned, which stimulates new growth and the humidity is high. Invading the foliage and moves into the twig, Phomopsis forms a canker that restricts the flow of water to the branch tip, resulting in death of anything beyond the canker.