This greatly reduces … This disease causes needles on Colorado Blue Spruce to turn a purplish brown color before dropping from the branches prematurely. It is most common in trees growing outside of their native range. I have a dwarf blue spruce that is about 10 years old, which has begun dropping needles at an alarming rate. Don’t leave behind protruding stubs -- they invite insects to take up residence in your tree and provide easy entry for disease pathogens. The bottom branches are bare and dead, and the disease has spread to all but this year's new growth. Use a magnifying glass to check the blue spruce’s needles. The bugs feed on bark tissue, needles and twigs. The appearance of small black spots, premature needle loss and a thinning canopy can be signs of Rhizosphaera needle cast. 2. Keep the Christmas spirit alive year-round by adding blue spruce (Picea pungens) to your landscape. Wanke holds a Bachelor's of Arts in journalism from the University of Wisconsin-Madison. Caused by the fungus Phomopsis occulta, the disease attacks new shoots, leading the tips to curl, turn pink and then brown before the needles fall to the ground. Rhizosphaera needle cast (Rhizosphaera kalkhoffii) is a foliar disease of spruce trees. Some browning and shedding of inner needles is normal in the fall. Adults resemble moths and lay eggs on the needles. The infectious fungal disease starts near the base of the tree and spreads upward. The needles turn brown, and just touching the tree causes them to fall off. What Is Causing the Hinoki Cypress to Turn Yellow? Recently, he told WKBN news that his “trees weren’t looking very good. If the tree is infected with Phomopsis tip blight, you'll see cankers in the areas exposed by the knife. © Copyright 2020 Hearst Communications, Inc. Be careful when trimming branches. Use a magnifying glass to check the blue spruce’s needles. Technically, mites are not insects, but are related to spiders. The ornamental evergreen’s exceptional height, distinctive needles and celebrated conical shape make it a popular pick as a focal point, living privacy screen and seasonal must-have. Examine the blue spruce for clumps of dead needles. Carefully inspect the blue spruce’s lower branches. Her work has earned her multiple Edward R. Murrow Awards and the Aircraft Owners and Pilots Association National Max Karant Journalism Award. The appearance of small black spots, premature needle loss and a thinning canopy can be signs of Rhizosphaera needle cast. The larvae feed on the needles, causing discoloration, entrance and exit holes and premature dropping. Michele Wanke is an Emmy award-winning journalist who has been writing and reporting about travel and garden trends since 1996. Prune sick trees during dry weather. Needles dropping from Blue Spruce. Also, sterilize shears after using them on infected trees. Learning how to tell when the tree is sick will help you preserve its visual appeal throughout the year. If the needles are reddish-brown and connected by a web, the tree may be infected by the spruce needleminer. Look for reddish-brown insects with elongated snouts crawling out of holes in the blue spruce’s shoots. Environmental factors can influence this cycle as well; for example, a tree that is under stress from things like drought, soil compaction or excessive moisture will enhance needle drop. Four years ago, Ron Linger of Ohio planted 100 blue spruce trees. It can take up to 15 months for the needles to show visible symptoms after the initial infection. Spruce spider mites cause needle discoloration and eventually kill needles, which can be mistaken for a needlecast disease (Photo 7). Iowa State University Extension and Outreach: Common Diseases of Blue Spruce, Ohio State University Extension: Rhizosphaera Needlecast on Spruce, Michigan State University Cooperative Extension Service: Phomopsis Canker of Spruce, University of Idaho College of Agriculture and Life Sciences: Management of White Pine Weevil in Spruce, United States Department of Agriculture: Forest Health Protection and State Forestry Organizations: Management Guide for Other Needleminers. During most years, the browning and needle drop is hardly noticeable. Needle drop naturally occurs seasonally in blue spruce. Shave sections of bark with a sharp knife if you notice glistening droplets or resin on the blue spruce’s branches.