Orange nasturtiums, one of many effective natural pesticides, will repel cucumber beetles, aphids, and Mexican bean beetles.
PHOTO: STAN DOWNS AND JOANNE PAVIA
By midsummer, most gardeners expect their months of mulching, tilling, composting, seeding, and weeding to begin to
pay off at last. Hungry horticulturists, however, aren't
the only creatures who've been keeping a watch on the
maturing produce, because July and August are also—in
most parts of North America—the peak of the "pest
season," a time when beetles riddle cuke plants,
hornworms strip tomatoes, and raccoons demolish corn.
But even if your crops are under siege by a veritable army
of produce plunderers, there's no reason to lay on a heavy
chemical hand. Numerous hazard-free, natural pesticides can help gardeners bring in big, healthful
harvests to feed their families. Of course, some remedies
are best employed at the beginning of the growing season
(an ounce of prevention, you know). And now—while the
results of not having taken protective measures at planting
time are all too obvious—is a good time to plan next
season's campaign. However, I'm also going to provide you
with a few ideas on how to discourage the bandits that may
be chomping on your crops at this very moment!
Protect Squash, Corn, and Tomatoes
You can, for example, guard your maturing cucumbers and
squash by using a handy kitchen discard: onion skins!
Simply strew a big handful of these leftovers loosely
across the top of each hill, and let the legendary Allium
pungency drive away the most stubborn of cucumber beetles
(as the skins decay, they'll add valuable organic matter to
For even more protection, you might border next year's
hilled areas with orange nasturtiums (Tropaeolum majus),
then further guard the mature plants by spraying a mix of
equal parts of wood ashes and hydrated lime in water on the
upper and lower surfaces of the spreading foliage.
Early in the year, you can fortify your future tomato
territory by sowing dill (Anethum graveolens) and borage
(Borago officinalis) to repel hornworms. Needless to say,
you'll enjoy these two useful and flavorful herbs for
themselves, as well as for their ability to protect your
One of the high points of summer—at least around my
house—is the first menu that includes field-fresh
roasting ears dripping with butter ... and one of the low
points is finding out that raccoons, squirrels, or earworms
got to that dinner before we did! To prevent such a
catastrophe, consider trying a few of the following plans
If your acreage allows, you might want to surround 1982's
crop of golden-eared goodies with a "soybean trap," which
will tempt any furry four-footed invaders to fill their
bellies with beans before they reach the succulent maize.
(For maximum efficiency, choose a soybean variety that will
mature when your corn does.) In addition, you'll find that
nasturtiums (which also repel aphids and Mexican bean
beetles), marigolds, and mustard rebuff numerous gnawing
pests by their color and pungent aroma. This year, you can
keep most of the competition away from your roasting ears
if you just walk through the patch, putting a pinch of
cayenne pepper on the silks.
Some folks also place crumpled newspapers between the rows, scatter sections of garden hose cut in one- to
threefoot lengths (to resemble snakes), hang pieces of
a broken mirror about, string Christmas tree lights
through the rows (who cares what the neighbors think!), and even play tape recordings of shotgun blasts to
discourage would-be produce pirates!
Mighty Marigolds and Mole Destroyers
While both French and African marigolds (Tagetes erecta)
help rid soil of nematodes, Mexican marigolds (Tagetes
minuta) apparently exude a substance from their roots that's
actually toxic to certain invasive weeds! Try sowing the
potent flowers as a cover crop this autumn. Then, when next
year's planting time rolls around, the posies can be turned
under for one of the finest, most soil-cleansing green
manure crops your ground could hope for. Tagetes minuta is
also repellent to rabbits, and destroys innumerable
soil-born pests. So be extravagant with the flowers. Scatter
them throughout your orchard, surround your roses with
them, and use some of the foliage to brew up a "tea" to
spray localized pest-infested areas.
If your midsummer plot is under attack by any below-ground
burrowers, you might want to plan to have a few mole plants
(Euphorbia lathyris) growing around the edges of your
garden next time around. The exotic-looking biennials with
their milky, latex-like sap (it's now being considered as a
potential source of petroleum substitutes) have long been
known as gopher deterrents ... and they'll sow themselves
the second year, providing you with seedlings to place in
other mole-ridden spots.
Two other plants that can be sown to help eliminate moles
are the castor bean (Ricinus communis ... which also fends
off flies and mosquitoes) and the common dandelion
(Taraxacum officinale). Castor bean seeds, however, are
poisonous, so be sure to caution neighborhood youngsters if
you grow this plant.
Slugs, Beetles, and Moths
Slugs, which are among the most damaging above-ground
pests, can be discouraged with a preparation made from
silicon-rich horsetails (Equisetum arvense). Once dried,
the plants produce a potent slug repellent powder that's highly distasteful to the
slimy slitherers. (You can also place discarded cabbage
leaves and grapefruit rinds—or even old
boards—throughout the garden in the evening. When day
breaks, check underneath the upsidedown "slug domes," remove the occupants, and either add them to your
ducks' breakfast menu or squash them.)
And, if Japanese beetles appear to be your primary enemy,
plan to plant castor beans, white-flowering
geraniums, zinnias, and garlic throughout your garden area
For more general purpose garden guarding, consider the
roadside herb yarrow (Achillea millefolium). It not only
repels a number of pests, but is commonly believed to
enhance the growth and flavor of plants growing nearby.
Furthermore, Achillea's friendly qualities can be utilized
throughout the year if you simply brew the foliage into a
liquid fertilizer and water periodically with the "tea."
When your cole family vegetables face an invasion of
cabbage moths and their larvae (which can mutilate plants
in a few short days), rely upon an item from your kitchen:
Simply pour soured milk over the young cabbages, etc. to
keep the moths aloft and the worms away.
Your special, tender greenhouse tenants need protection,
too, so always allow a few shoo-fly plants (Nicandra
physalodes) to occupy several places of honor in your
solarium. The attractive, fast-growing annuals are toxic to
all pests that chew them, and rebuff the white flies that
often plague enclosed gardens.
Homegrown pesticides can also keep your kitchen and food
storage areas free of unwanted guests. For example, a
couple of bay leaves (Laurus nobilis) in the bottom of
grain containers will keep them bug-free, and tiny cloth
bags of ground black pepper will prevent weevils from
infesting dried beans. Furthermore, if silverfish are
setting up housekeeping in your cupboards, just place
fragrant leaves of costmary (Chrysanthemum balsamita) in
each section of the cabinets to make the squatters move on.
Moderation in All Things ...
Resourceful gardeners have found innumerable common plants
that have pest-chasing abilities. Sprays, for instance, can
be made from many different species and used for a variety
of purposes: The alkaloid exudates from nearly every type
of tomato foliage will deter aphids. Stinging nettle
(Urtica dioica) spray encourages healthier plants. A
turnip or anise mist will rid your crops of spider mites
and aphids. Basil spray discourages flies (and mass
plantings of the herb around a porch or patio will also
repel the insects). Onion, garlic, horseradish,
mint, and chamomile flower sprays all have bug-chasing
qualities of their own!
Even as you put such organic pesticides to use, though,
keep in mind that an insect or two here and there will not
pose a threat to your growing grounds. In small numbers the
invaders simply provide food for natural predators
such as swallows, each of whom may consume 2,000
insects a day! In fact, Mother Nature maintained a precious
and delicate balance long before we decided to intervene.
It's the duty of every concerned gardener to respect that
balance, and to use repellents—even natural ones—only when
populations of pests threaten to become excessive.
EDITOR'S NOTE: Author Diane Downs sells most of the plants
listed in this article, plus some 150 varieties of live
herb,. plants, herb seeds, and herbal products.