Organic News 3

nce these hedgerow plants are established, they
“Ocan bloom for a long period and produce a
large quantity of flowers with high-quality nectar,” says Rachael
Long, farm adviser with the University of California
Cooperative Extension Service. “Hedgerows provide shelter
from wind and cold, too, as well as alternate prey species, which
is especially important at the end of the growing season when
beneficials need a place to overwinter. It encourages them to stay
in the area.”
In a home garden setting, even a small mixed
border of shrubs, grasses and perennial flowers
should achieve similar results. Select plants with different
bloom times, advises Long. The closer the planting is to
garden crops, the better, although beneficials will travel as far
as several thousand feet if necessary.
One note of caution: Letting the margins of
your property go “wild” with weeds is not
necessarily the kind of diversity you want to encourage. “We
found that weedy, semi-managed areas actually were a resource
for insect pests, while managed hedgerows with native plants
had fewer pests and more beneficials that moved to nearby
crops,” Long says.
5. COVER MORE GROUND
Cover your soil with an organic mulch or cover
crop. Bare ground exposes beetles, spiders and
other beneficial garden insects to climate extremes (temperature,
wind, humidity) that can threaten their survival. “Use
any locally available organic mulch,” Gardiner says. “As long as
it helps retain moisture, is well-aerated, and is not infected with
fungal pathogens, it will protect the beneficials from the sun and
also provide food for some predators as it decays.”
Cover crops such as buckwheat, cowpea, sweet
clover, fava bean, vetch, red clover, white clover
and mustards can also provide food and shelter for beneficials.
“The key is to make sure that both the cover crop and
food crops overlap for at least some of the time, so beneficials
can move directly from the cover crop to the crop pests,” says
Robert Bugg, a University of California, Davis entomologist
who has been studying the relationship between plants
and beneficials for several decades. At the end of the season,
ignore the conventional advice to remove all spent vegetation.
If you know you have a pest that will overwinter in
the debris, go ahead and remove it or till it under. But if
not, leaving the debris is better because beneficials will seek
shelter in it. Bunch grasses and clumping perennials such as
comfrey provide especially good winter shelter for a number
of beneficial insects.
6. WATER WORKS
Provide shallow, gravel-filled dishes of water
in your garden if you don’t have other water
sources such as ponds or wetlands nearby to support beneficial
insects (including native bees). Be careful to change the
water frequently to avoid creating a habitat for mosquitoes.
Better yet, try growing the cup plant (Silphium perfoliatum),
which holds water in its leaves.
7. USE ORGANIC INSECTICIDES SELECTIVELY
Insecticides are designed to kill insects, and even
natural, plant-based pesticides such as pyrethrum
can kill beneficials. Use only pesticides approved for use
by organic growers, use them as a last resort, and use them
selectively. Besides, experts say having a few insect pests in
your garden isn’t so bad anyway — they help keep the good
guys hangin’ around, hungry for more.
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