1. Good Organic Gardening - January-February 2016

for both users and the environment, it
provides gardeners with an effective option
for protecting homegrown produce.
B. thuringiensis is available as several
different strains or subspecies, each
having a specific toxicity to particular
types of insects. The Bt most commonly
available to home gardeners is Bacillus
thuringiensis subsp. kurstaki, often known
as Dipel. Home garden products are
usually wettable powders that are mixed
in water and sprayed over foliage.
Bt is not absorbed into plant foliage
and is degraded by UV light, so does
not persist on plants. Bt-based products
usually don’t have a withholding period,
so homegrown produce sprayed with Bt
can be eaten straightaway (rinsing before
eating is always recommended,
of course).
For home gardeners, the most common
caterpillar pests include cabbage white
butterfly, cabbage moth, armyworm,
budworm and loopers.
Bluish-green cabbage white butterfly
caterpillars can devour mountains
of vegetables such as cabbage,
kale, cauliflower and broccoli, leaving
Dipel | SAFER SOLUTIONS
Bt targets particular
receptor sites in the
caterpillar and has no
effect on humans as we
lack those receptors.
Bt also does not affect
beneficial insects, pets
and wildlife.
Cabbage white butterfly caterpillar
feasting on kale
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