Trees/Shrubs- Spruce Disease

Trees/Shrubs- Spruce Disease

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Cytospora Canker is the Spruce's most important disease.

It is caused by a fungus and is frequently found on Norway spruce and Colorado blue spruce and its cultivars. It is sometimes found on Douglas fir, hemlocks, larches and balsam fir. It is often associated with weakened trees, trees with injuries and trees growing in poor conditions. It is seldom found on young, vigorous trees.

Sometimes Cytospora damage can be confused with mite damage.

Symptoms
Dying of a lower branch with subsequent needle browning is usually the first symptom. The dead needles may remain on the branch or fall off. Higher branches may be affected as the disease progresses. The actual cankers are often seen at the base of branches near the main trunk. Trunk cankers can develop which will result in girdling and death of the tree.

The bark of the cankered areas is not visibly different in colour nor does it become sunken. Resin flow is usually associated with Cytospora canker and the white patches are quite conspicuous on the bark. Resin flow can, however, be associated with any injury to branch tissue.

Control
There are a number of things that can be done to reduce cytospora canker:

Maintain tree health. The two most important steps are to water and fertilize on a regular schedule.

An amount equal to 2 inches of rainfall is needed every 2 or 3 weeks in one complete heavy soaking to the feeder root area. Turn the hose to a drip and let the water soak in slowly.

Feed the plants regularly. Fall feeding in late October to mid-November is the best time. Deep root feeding is an excellent way. Spring or early summer feeding is also good. Granular or water soluble fertilizer can be used.

Control insects and mites, especially spruce gall adelgids and spider mites.

Avoid any disturbance to the root system that will result in injury or poor root growth. Avoid bark and stem injuries.

Selectively prune out branches that restrict air movement near the base of the tree. These low branches are often wounded by lawnmowers, pets and general traffic. Weak and injured branches should be removed flush with the tree trunk. Pruning during wet periods can spread the disease; therefore prune only when foliage and trunk are dry. Pruning tools should be disinfected with 70% alcohol or a mixture of 1 part bleach and 9 parts water.

No chemical control measures are available. Some reports indicate that a Bordeaux mixture or other fungicides containing copper and sprayed after removing diseased branches may help retard disease spread. Early spring or late fall applications may prevent further spread.

Vertically mulch to relieve compaction, poor aeration, and inadequate water penetration.

If you have a lawn/tree/shrub that needs some Tender Loving Care- get The KING OF GREEN:

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