Gardening Tips: Protect Against Sporotrichosis, Stop Apple Scab, and Prevent Strawberry Mold

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.