What Is Wrong With My Incense Cedar?

Are there any holes in the trunk; brown, pink, or white resin masses may be visible around entry holes; canopy may have turned yellow to red?

Have the seed of your tree been sucked dry?

Are there any dark brown streaks on the wood where the bark had separated from the tree, silver or whitish flecks may appear on the inner bark surface?

Are there any reddish-brown streaks on the outer and inner bark, as well as gum or dark sap oozing from the diseased area?

Mountain pine beetle (Dendroctonus ponderosae) attacks the mid-trunk of large trees. Boring activity causes the canopy to turn yellow to red within 8-10 months of an attack. Brown, pink, or white resin masses appear where the beetle has bored into the trunk. Improving host vigor often makes trees less susceptible to this beetle, which typically seeks stressed, damaged, or older trees. Leave adequate space between trees and thin susceptible stands if necessary. Sprays are available for short-term or preventative control.

Western conifer seed bug (Leptoglossus occidentalis) consumes large amounts of seed by sucking out the pulp. Large numbers of adults may suddenly invade buildings in search of overwintering sites or congregate on the outside of structures. Exclude the insects from buildings with well-fitting window screens and doors.

Annosus root disease infects the roots or butt of the host tree. May cause extensive root decay and gradual tree death. Bark may separate from the tree, revealing dark brown streaks on the wood beneath. Silver or whitish flecks may appear on the inner bark surface, with small whitish mycelial growths on the outer bark. Avoid wounding trees, as wounds may become infection sites. Borax can be applied to fresh cuts to avoid infection.

These symptoms indicate fungal disease Phytophthora Root and Crown Rot. Phytophthora pathogens are favored by wet conditions, and the risk of disease can be reduced with good water management. The disease tends to affect plants in poorly drained areas, where susceptible plants are surrounded by standing water or saturated soil for prolonged periods. Provide adequate drainage and know the water needs of individual plants.

Dry pocket rot causes heartwood to rot. Early indicators include yellowish-brown discoloration in the heartwood. Advance decay indicated by round-ended pockets of dark brown, crumbly dry rot with long vertical shrinkage cracks. Dry pocket rot is mainly a problem on older trees and trees growing in excessively wet conditions. Adjust irrigation and/or drainage as necessary. Avoid wounding trees, as hosts become infected primarily through open wounds, large open knots, and broken branch stubs.