What green-friendly lawn and garden pesticides are
available today?
Pesticides have greatly boosted agricultural yields
over the last half century, so it is no wonder, given the commercial
availability of many of these synthetic chemicals, that American homeowners
apply 100 million pounds of the stuff each year to make their own gardens
grow bigger and faster, too.
But the downside of using such chemicals is that they
can poison people and pets as well as backyard wildlife: “Common
insecticide ingredients such as 2,4-dichlorophenoxyacetic acid
(2,4-D), atrazine, and dicamba have been shown to harm mouse embryos
at times equivalent to the first week after conception in humans,”
says Erica Glasener of The Green Guide. In light of such revelations, home
gardeners are fast discovering the benefits of avoiding chemicals in favor
of natural, less toxic alternatives.
Before thinking about applying pesticides, gardeners
can design (or redesign) their gardens to make the most of native plants
that have evolved over eons to thrive in local conditions without synthetic
aid or lots of water. Choosing native plants appropriate to your elevation,
soil type, drainage, and sun exposure will naturally repel many common
pests and also reduce the propagation of invasive exotic species.
Similarly, embedding your plants in healthy soil
replete with beneficial insects and worms can also help reduce the need for
pesticides. Laura Moran of Mainstreet.com suggests that home gardeners
compost their vegetable food waste, which is chockfull of nutrients that
plants love, and mix it into existing soil to give the garden a healthy
boost. “Aside from stimulating healthy root development,” she
writes, “the addition of rich compost also improves soil texture,
aeration, and water retention.” It also provides a nice home, she
says, for the beneficial bugs that are destroyed along with the bad ones by
chemical pesticides.
If pesticides are necessary, there are a handful of
organic varieties available. Bacillus
thuringiensis (“Bt”) is a
naturally occurring bacterium that is lethal to most leaf-eating
caterpillars on trees, shrubs, flowers, and vegetables. According to
gardening writer Jeff Ball, it is harmless to all other insects, animals,
and human beings. It comes in a powder form for use as a dust or, when
diluted with water, as a spray. Organic chemists have formulated varieties
of Bt to kill mosquitoes or potato beetles as well.
To control slugs in an environmentally friendly
manner, The Green Guide’s Glasener suggests recycling the black cell packs that
vegetables and annuals are sold in by placing them (empty) upside down near
the bases of plants. “Each morning, check the containers for pests,
and if you find any, simply throw the container away with the pests
inside,” she says. You can use hollowed-out grapefruit rinds in a
similar manner around the bases of plants, disposing of them if they turn
up any slugs.
Pet owners may already be familiar with insecticidal
soaps used to control fleas. Some of these soaps can also be used in the
garden to repel insects. For more information, consult a local nursery
specializing in organic methods and native plants. Using the free online
Native Plants Nursery Directory, find one near you.
For more information:
The Green Guide, www.thegreenguide.com; MainStreet.com, www.mainstreet.com;
Native Plants Nursery Directory,
www.plantnative.org/national_nursery_dir_main.htm.
Send questions to Earth Talk, care of E/The Environmental Magazine,
P.O. Box 5098, Westport, CT 06881 or e-mail earthtalk@emagazine.com.
This article appears in Jul 17-23, 2008.
