All these species are classified into three clades, as given below. Rhizosphaera often accompanies other problems. Infection, which begins in spring, usually appears first scattered among the lower branches and may cause severe loss of needles. • Cooley spruce galls are mainly on Colorado blue spruce and white spruce. Keep in mind that there may be more than one problem on a tree. List of Different Types of Spruce Trees. The Picea genus includes thirty-five extant species, out of which the Brewer’s spruce has a basal position, after that come the Sitka spruce, and then the other species. Blue spruce trees are susceptible to an infectious needle disease caused by the fungus Rhizosphaera. Prune out green galls on small spruce. It is most common on Colorado blue spruce. From a distance, the tree looks healthy with vigorous growth. Clade I. Brewer’s spruce (Picea breweriana)Sitka spruce (Picea sitchensis); Engelmann spruce (Picea engelmannii); White spruce … Non-native blue spruce are most heavily impacted by needle diseases, particularly Rhizosphaera needle cast. Last year (2017) was a very wet year all throughout the … Linda: Rhizosphaera needlecast does very well during wet years. … Al: Why does this seem to be such a problem this year? FORESTRY IVISION … • Eastern spruce galls mainly affect Norway and white spruce. This disease can also affect other spruce species and conifers. Blue spruce is most often infected, while white spruce is moderately susceptible and Norway spruces are resistant to this disease. White spruce are classified as intermediate in susceptibility to the disease and Norway spruce are relatively resistant. Fungal spores are spread … Blue spruce trees are much more susceptible to the disease than white spruce, but we’re seeing heavily impacted white spruce this year too. Find the pineapple-shaped galls at the base of new shoots. But upon closer inspection (Photo 3), there are sections of needlecast and branch death around the base of the tree that are beginning to become noticeable, hence the reason the photos were taken in 2009. The disease, referred to as Rhizosphaera needle cast, is the most common problem seen on blue spruce samples that are submitted to the Plant Disease Clinic. Colorado Blue Spruce Problems. Lookalikes: Spruce spider mite. Management • Management is not necessary on spruce with healthy crowns. In Photos 4 and 5, … Find them at the tips of new growth. Page 2 of 4 Rhizosphaera and stigmina needlecast of spruce Both of these fungal diseases cause purpling, then death and dropping of second year and older spruce needles. Avoid planting spruce in heavy shade. The Colorado blue spruce, or Picea pungens, is a favorite choice for Christmas trees as well as a robust and substantial addition to a landscape. Norway spruce is more resistant but we’re even seeing some of those trees being impacted. In Photos 1 and 2, you can see a Colorado blue spruce from its east and west aspects in July 2009. Rhizosphaera needle cast is the best-known of these diseases, but another fungal disease known as Stigmina needle cast, caused by Stigmina lautii, has also been common and causes the same type of symptoms.