AKRON, Ohio —
You might be working harder in the garden than you have to.
By taking cues
from nature, you can cut down on insect damage, diseases and other
problems that often plague food gardens. Add a little human ingenuity,
and you can even extend the growing season and skip much of the
weeding and watering that make gardening a chore.
Joe Kovach
preached those methods as an expert in integrated pest management with
the Ohio State University Extension, and he put them to work in
research plots where he studied the best ways to grow food on urban
land.
Now that he’s
retired from OSU’s Ohio Agricultural Research and Development
Center, he’s using his methods at Wooster’s GreenPoint Garden, a
plot on the city’s north side that grows food for Wooster Community
Hospital.
Kovach, who
holds a doctorate in entomology, designed the garden on Friendsville
Road and volunteers as its director of operations. Although GreenPoint
is large — about three-quarters of an acre — he said the methods
used there can improve even the smallest backyard garden.
At the center of
his strategy is polyculture, a growing method that imitates the plant
diversity found in nature.
In a natural
setting, plants of different sizes, genetic makeups and flowering and
fruiting times all co-exist in the same area, Kovach explained. That
natural variety creates a system of checks and balances, keeping
diseases and insects from spreading out of control.
"No matter
what garden system you have, it’s an ecosystem," he said.
"We want ecosystem stability."
Polyculture isn’t
a perfect system. As Kovach likes to say, "Nature bats
last." But while it’s impossible to eliminate problems
entirely, an ecologically stable garden will be better able to fight
off trouble and bounce back when it occurs, he said.
Here’s what he
recommends:
PLANT A VARIETY
OF FOODS
Plants belong to
different families, or groups that share a similar genetic makeup.
Broccoli and cabbage belong to one plant family, for example; tomatoes
and peppers belong to another.
Certain plant
families are prone to certain pests, so mixing things up in the garden
decreases the chance of one insect or disease wiping out your entire
crop.
Kovach said most
backyard gardeners achieve that diversity without even trying, just
because they like to grow and eat a variety of foods.
Still, it’s
helpful to keep plant families in mind as you’re plotting your
garden, he said. If you can keep plants in one family in the same row,
it’s easier to rotate crops each year, a process that improves soil
fertility and mitigates disease problems.
The accompanying
box tells which plants belong in which family.
MIX UP PLANT
HEIGHTS
Just as insects
differ in what they like to eat, they also differ in where they prefer
to hang out. Planting tall and short crops in close proximity creates
different layers of habitat, resulting in a more inviting environment
for a variety of beneficial insects.
And because bugs
tend to stay put once they find plants they like, a spatially diverse
habitat does a better job at confining pest damage, Kovach said. It
makes it harder for undesirable insects to find other plants to feed
on.
Kovach suggests
varying plant height row by row — for example, planting a row of
short plants such as strawberries, then a row of tall plants such as
tomatoes, then another row of short plants like broccoli.
He said you can
also create plant height artificially by using vertical gardening —
that is, planting in containers attached to fences or other upright
structures.
At GreenPoint
Garden, for example, beets and onions grow in long trays hung in two
rows from heavy wire fencing called cattle panels. Peas are planted in
the ground at the base of the fence. Even though those plants are all
fairly short, the mass of plant material extends all the way from the
ground to 5 feet or so above it.
GreenPoint’s
metal trays aren’t commercially available, but flower boxes or
gutters would work just as well, Kovach said. Make sure the containers
have holes in the bottom for drainage.
The vertical
gardening system has a couple of bonuses, he noted. It allows him to
triple his yield compared to plants grown strictly in the ground, and
it also makes gardening easier for people with limited mobility.
PLANT AT
DIFFERENT TIMES
Forget about
planting your garden all at one time. Kovach recommends succession
planting, or planting in stages so a crop matures at different times.
By doing that,
you reduce the likelihood of an entire crop being wiped out by a
disease or insect, he said. An insect that attacks your early beans,
for example, might be gone by the time the next wave matures.
Besides,
spreading out the harvest means you’ll have things to eat over a
longer period. You won’t be begging the neighbors to take your extra
zucchini off your hands one week and then wishing you had some for
supper a couple of weeks later.
BE GENTLE ON THE
SOIL
It used to be
common practice to till a garden each year before planting and to
continue tilling during the growing season to control weeds. But newer
research shows excessive tilling disturbs the structure that allows
air and water to move through soil, and it kills or disrupts the
earthworms, insects, microorganisms and other beneficial beings that
live in the soil and support plant life.
Kovach avoids
the need to disrupt the soil by covering his planting rows with
landscape cloth to prevent weed growth. He uses a propane torch to
burn holes in it just large enough to plant through and accommodate
the stems of the mature plants, but not so big that weeds seeds can
get in easily.
The landscape
cloth needs to be swept periodically to remove weed seeds, so there’s
less chance they’ll find their way into the openings, he said.
Not only does
the landscape cloth virtually eliminate weeding, it also protects the
plants from disease-causing organisms that can splash up from the soil
when it rains.
He recommends
buying good-quality landscaping cloth with a 15- to 20-year guarantee,
so it will hold up over time.
COVER UP
Kovach likes to
use low tunnels and row covers to protect plants from the cold,
allowing him to plant earlier.
Row covers are
the simplest to use. They’re pieces of nonwoven fabric that are laid
over the plants and act as blankets, capturing warmth from the soil
but still allowing rain to penetrate. Kovach said row covers provide
enough protection to allow planting a few weeks early and can be kept
in place most of the season to protect the plants against destructive
insects.
Low tunnels are
more like miniature, unheated greenhouses that cover rows of plants.
They’re made from metal arches or similar frames a foot or two high,
covered with sheets of plastic.
The low tunnels
at GreenPoint were created by bending metal conduit into arches and
slipping the ends of the pipes over rebar posts driven into the
ground. Plastic is draped over the arches and held in place with
spring clips.
The plastic
raises the temperature inside the low tunnels enough to change the
growing conditions by an entire hardiness zone, he said. In other
words, plants grown under low tunnels experience conditions more like
Northern Tennessee’s than Northern Ohio’s.
The plants have
to be watered under the plastic until it’s removed when the weather
warms.
GreenPoint
Garden also uses high tunnels, which are similar to low tunnels but
large enough to walk in. They’re more common in large-scale growing
operations than backyard gardens.
(EDITORS:
STORY CAN END HERE)
———
OTHER TIPS
Kovach also
recommends these strategies:
—Plant grass
pathways between garden rows instead of just leaving them as bare
soil. The grass sucks up moisture so the paths don’t get so muddy
during wet spells, and it keeps dust down in dryer periods. You’ll
need to mow the grass periodically, however.
—If you have
problems with deer, groundhogs or other animals, put up an appropriate
fence. Nothing else works as well to protect plants from animal
damage.
—Consider
adding a drip irrigation system. It requires a little plumbing
know-how, but it eliminates the need to water and also keeps foliage
dry, cutting down on disease.
—Compost makes
great fertilizer, but Kovach isn’t opposed to using some chemical
products. If you do use chemical fertilizers, choose a liquid type. It
won’t burn plants the way granular fertilizers can, he said.