SEASONS OF THE GARDEN
RELATED CONTENT
By Greg and Pat Williams
You say you've been having a slugfest in your garden and
the organic slug remedies (like beer in saucers) aren't
working? Is it time to give up and reach for a chemical
poison? No! Recent English experiments have shown that
aluminum sulfate, a natural inorganic material
widely used to acidify soil, works as well as — or
even better than — the standard methiocarb and
metaldehyde slug molluscicides (mollusk toxins).
Furthermore, aluminum sulfate costs less than the synthetic
substances and is quite easy to apply.
In the British tests, all the molluscicides evaluated
— natural and synthetic — provided adequate
protection for four days, then slug damage began to recur.
Hence, frequent applications may be necessary. However,
since aluminum sulfate seems to act more as a repellent
than a poison, slug populations might take a long time to
build resistance to it.
Aluminum sulfate powder is sold at most garden centers as a
soil acidifier. Apply five to 10 pounds per 1,000 square
feet for slug control. (About 50 pounds per 1,000 square
feet is needed to lower pH a point — and you can
always add lime to bring pH back up. )
Research Briefs
Sterile Darrows. The Darrow is perhaps the
best thorny blackberry cultivar for the eastern U.S. But if
yours bear poorly or not at all, they may be victims of
Darrow sterility disorder. DSD seems to be
genetically based (even tissue-cultured plants can be
afflicted) and cannot be cured. So make sure your
blackberry suppliers obtain their propagation materials
only from highly fruitful plants.
Don't microwave test soil. University of
South Dakota researchers report that using a microwave oven
to dry soil test samples significantly alters the results
for organic matter content, pH, nitrogen, potassium, sulfur
and cation-exchange capacity.
Low-mow lawn grass? Jan Wiejer, a
geneticist at the University of Alberta, has developed
several new grass cultivars — including fine fescues,
bluegrasses and wheatgrasses — that grow less than
six inches over an entire summer. However, some specialists
question whether the "miracle grasses" will work well in
the U.S.
