Root Collar Excavations and Examinations

A thorough inspection of the Root Collar, where the roots flare out into the soil, is recommended for any tree to be climbed, or for any tree that needs further evaluation for disease or hazard.

An examination of the root collar includes the removal of all soil around the trunk. If the soil has been raised, this requires removing the soil down to approximately six to twelve inches below the original grade. This exposes the major roots for inspection. These roots are then examined for signs of healthy or dead bard, and/or decay. Care is taken to pull dirt away from the roots rather than risk injury to them by driving a tool into the soil. Soil embedded in the coarse bark of the trunk is removed with a paint scraper and whisk broom. Rotted bark is removed to the live phloem. Dead bark is removed with a chisel to the edge of live tissue, or callus. Lawn is not replaced closer than twelve inches from the trunk. This reduces the changes for injury to the main anchoring roots by lawn mowers, and eliminates the need for irrigating near the trunk.

If disease (dead, yellow to dark brown phloem), or decay is found, an assessment of the extent of disease or decay is made and recommendations and treatments developed.

If the extent of decay is considered significant enough to present a potential hazard, the tree is recommended for removal.

Diseased roots are usually left open and exposed for at least one growing season, or until callus has begun to form. Healthy roots are recovered with soil to the original grade; infested areas are left exposed for treatment.

Fire Blight

Fire Blight only affects members of the rose family (rosaceous). It was the first plant disease shown to be caused by bacteria and transmitted by insects. Symptoms include blight (sudden wilting and/or dying) of blossoms, fruitlets, spurs, and leafy shoots, and the formation of cankers that cause dieback of twigs and branches.

In the case of blossom blight, flowers (individual or clusters) appear watersoaked. They quickly droop, shrivel, and turn brown (many remain attached). Leaves on twigs and branches remain attached. They are dead from blossoms into pedicels and fruit spurs.

Infected (blighted) parts appear black in places and brown in most others. They look scorched by fire, hence the name "fire blight."

The infection slows in twigs and branches, but includes discrete cankers and small, brown/black, slightly sunken areas. In dormant season, the edges often crack, but in growing season, active margins may appear slightly raised and/or blistered.

Fire blight spreads by water, air, insects, birds, and humans. The plant can ooze cream onto the carriers (wet) or produce bacterial strands (dry).

You can prevent the spread by pruning infected parts past discoloration (eight to twelve inches below visible infection). Or, use a copper spray with a low dilution rate at full bloom.