Dwarf Alberta Spruce black stems

(Question)

Hi, this is truly the worst year for problems with plants in my garden…My Dwarf Alberta Spruce all of a sudden developed blackening of the stems and I had to remove some branches. It looks like a pest or a fungus. Any suggestions for controlling this will be appreciated. Many thanks for all you help!

(Answer)

Cankers on the branchlets that are oozing resin, suggest spruce canker, Leucostoma kunzei, which is a very common issue with Alberta Spruce. In winter, prune out infected branches to the nearest unaffected lateral twig. Clean your pruners carefully between every cut (70% alcohol) so as not to spread the infection. If you prune at other times, make sure the weather is dry to limit the spread of spores and treat pruning wounds with a sulfur tree dressing or similar.

Fertilize to stimulate growth in spring. However, do not cultivate the soil around the tree and avoid root disturbance or any activity that will weaken the tree. Water appropriately.

Currently, no fungicides effectively control this disease and trees can often die despite the proper pruning, fertilizing and watering. Also even if they do recover, the tree can become quite unsightly as evergreens rarely fill in gaps that have been pruned out.

For further reading on diseases of spruce see the following:https://www.mortonarb.org/tree-plant-advice/article/748/spruce-diseases.html