Management Strategies: Fighting Cytospora Canker in Dryden

For Dryden residents, protecting our Blue Spruces from Cytospora canker starts with early detection. Knowing the signs of this fungal disease can help us take action before it's too late.

The first sign of Cytospora canker is often needle discoloration. Needles on affected branches turn yellowish-brown and eventually fall off. This typically starts in the lower branches and progresses upward.

Look for cankers on the branches or trunk. Cankers are sunken, dead areas of bark that may be slightly discolored. The most telling sign is the presence of white resin flow from these cankers. This resin, often mistaken for sap, is the tree's defense mechanism against the fungus.

As the disease progresses, entire branches may completely die, creating a distinctive pattern of dead branches amidst healthy growth. Depending on the health of the tree, in some years no branches may die, or only a single branch may die. But, it’s also possible to lose multiple branches in a single growing season. In advanced cases, the tree develops a thin, sparse appearance as more branches succumb to the disease.

No fungicides have been developed to combat Cytospora canker. To slow the progress of the disease it’s important to maintain the health of the tree. This is accomplished by fertilizing the tree to insure adequate nutrients are available in the soil for the tree. Also, watering the tree during periods of dry weather will reduce stress on the tree. Watering should be done with a soaker hose coiled under the canopy of the spruce tree.

Pruning branches from a spruce tree with Cytospora could spread the disease within the tree or from one spruce tree to another spruce tree. Any pruning tools should be sterilized between each cut. Sterilizing pruning tools can be done with a bleach solution.

It's important to note that Cytospora canker symptoms can be similar to other spruce problems seen in Dryden, like needlecast disease or spider mite infestations. If you're unsure, consider consulting a local arborist for a professional diagnosis.

Regular inspection of your Blue Spruces, especially in spring and early summer when symptoms are most visible, can help catch Cytospora canker early. Early detection and proper management can significantly extend the life and beauty of your trees, preserving Dryden’s Blue Spruce population.