DIRTY NEEDLES!

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SEASONS OF THE GARDEN

by GREG AND PAT WILLIAMS

YOU WON'T FIND WARNING LABELS on purchased trees and shrubs, but perhaps you should. The once-rare fungal infection called sporotrichosis has become a major concern to the nursery industry. Last year there were outbreaks of this potentially serious disease in 14 states.

The fungus that causes sporotrichosis can contaminate sphagnum moss and then enter the victim's bloodstream via small puncture wounds. Handling sharp-needled conifers is thus riskier than handling deciduous plants; still, you should wear gloves to protect against wounds when working with any plants packed in sphagnum moss.

Symptoms typically begin a week or two after infection, with red lesions on the skin of hands and arms. More lesions follow, and these can have discharges or can ulcerate. Sometimes there are severe complications. Treatment is simple—oral dosages of potassium iodide; unfortunately, many physicians do not diagnose sporotrichosis accurately. If you have been planting trees or shrubs (especially prickly ones) and have skin lesions that don't heal within a month, see your doctor and suggest the possibility of this tree planter's disease.

Research Briefs

Stopping apple scab.

An Indian horticulturist reports that spraying a 5% solution of urea, a soluble nitrogen fertilizer, on apple trees late in the growing season (but before leaf fall) can result in scab control comparable to that achieved by using fungicides. Synthetic urea, made from petroleum, is chemically identical to the urea in the animal urine, so homemade manure tea may make a good (and non-oil-based) substitute.

Stopping strawberry mold.

Canadian researchers have found that clipping and removing strawberry foliage can significantly reduce gray mold, Botrytis cinerea, the following year (the mold overwinters on dead leaves). It's probably best to clip leaves late in the fall so the root systems will have time to store abundant food reserves.