Corn
Gluten Meal: A Natural Herbicide
Controlling
weeds in an environmentally sound way can be a challenge in your garden and
lawn. Corn gluten meal is a natural
product that can safely inhibit germination of grass and weed seeds.
In
1985, Dr. Nick Christians, of Iowa State University (ISU), accidentally
discovered that corn gluten had preemergence herbicide activity. The control plot of a turf fungal study showed thin seeded grass stands
when pure corn gluten was used.
Further study by Dr. Christians and his graduate students lead to 4 patents on
corn gluten and its active components over the last 15 years. Currently over 20 companies are licensed by ISU to sell corn gluten as a
natural herbicide (US Patent 5,030,268; Re 34,594).
Corn
gluten is a by-product of wet milling process to make cornstarch. It is an animal feed for cattle, poultry, other livestock, fish and some
dog foods. It
also contains naturally occurring substances, which inhibit the growth of seed's
tiny feeder roots by causing a break down in the cell wall. The seedlings struggle to get enough moisture, which causes them to die
before they ever have a change to take hold. When used as directed, corn gluten acts as a preemergent natural
herbicide that will not harm beneficial insects, soil organisms, pond or stream
life. It is also safe around pets
and children.
Since
corn gluten kills only the roots of sprouting seeds, it can be used around
transplants and established vegetables, flowers, fruit, shrubs and lawns. It can be used even up to the day of harvest.
Once vegetable or flower seedlings have true leaves, it is then safe to
apply corn gluten.
Corn
gluten has another benefit. It is
10% nitrogen by weight in a slow release form. As a 10-0-0 fertilizer it can inhibit weed germination and feed your lawn
and garden nitrogen. (Additional
supplements of phosphorous and potassium may be needed, based on a soil test.)
The
only potential hazard that is documented so far is potential allergic reaction
from inhalation of dust with certain individuals.
Facts
Corn
gluten is a fine yellow powder, usually pelletized for easier application.
It
comes in 5 lb bags, but a 25 lb bag (blended with bone meal and potassium
sulfate from the organically certified Idaho mine) will be available this fall
from Necessary Organics.
It
is available at local stores, by mail order, or on the Internet under various
brand names including:
| Name/Distributors |
Licensed
Manufacturer |
Phone |
| BioWeed |
Bioscape,
Inc.
4381 Bodega Avenue
Petaluma, California, 94952
|
707-781-9233 |
| Concern®
Weed Prevention
Plus |
Necessary
Organics
8906 Wentworth Avenue South
Bloomington, MN 55420
|
800-468-2472 |
| Corn
Gluten Meal Weed Control |
Safe
Earth Lawn & Gardens
900 52nd St.
W. Des Moines, IA 50265
|
515-222-1997 |
| Corn
Weed Blocker |
Greenfire
2527A Hwy 32 West
Chico CA 95973
|
530-895-8301
800-895-8307 |
DynaWeed™
American
Natural Products Co.
Planet
Natural |
Soil
Technologies Corp.
2103 185th Street
Fairfield, IA 52556
|
515-472-3963
800-221-7645 |
| Earth
Friendly™ |
Cereal
Byproducts, Inc.
Mount Prospect, IL
|
847-818-1550 |
| GreenSense™ |
Rhode's
Services, Inc.
1651 Wall Street
Garland, TX 75041
|
972-864-1934 |
| Organic
WEEDZSTOP™ |
Fertrell,
Inc.
P.O. Box 265
Bambridge, PA 17502
|
717-367-1566 |
| ProPac™ |
Manning
Agricultural Center, Inc.
619 Julia St.
Manning, IA 51455
|
800-248-4409 |
| Safe
Earth Natural Weed Control |
Safe
Earth Lawn & Gardens
900 52nd St.
W. Des Moines, IA 50265
|
515-222-1997 |
| Safe
'N Simple™ |
Blue
Seal Feeds
P.0. Box 8000
Londonberry, NH 03053
|
603-437-3400
800-367-2730 |
| Safeway™ |
Lawn
Ranger
New Buffalo, MI
|
616-469-0667 |
| SUPER
ORGANIC "G" |
Winton
Graf
Bloomington, MN
|
612-887-0068 |
Suppressa™
Totally Organic Product Supply |
Hardesty
Organic Supply
252 Hedge Road
Menlo Park, CA 94025
|
650-325-5959 |
| Tiger
By The Tail™ |
Greener
Pastures
Minneapolis, MN
|
651-646-2900
800-798-1069
|
| WeedFREE™ |
Butterfield Gardens
Glen Ellyn, IL
|
630-393-1062 |
| Weed-Stopper
Plus |
Walt's
Organic Fertilizer Co.
1528 NW Leary Way
Seattle, WA 98107
|
206-297-9092
206-783-6685 |
W.O.W!®
(for without weed)
W.O.W!®
Plus
Granulated W.O.W!® |
Garden's
Alive!
5100 Schenley Place
Lawrenceburg, IN 47025 |
812-537-8650
812-537-8652 |
It
is patented as a preemergent herbicide. Feed
mills can not legally sell it for this purpose unless it is licensed by ISU.
Corn
gluten results in less weed seed carryover in soil and added nitrogen to feed
plants.
Areas
that gardeners want annuals and perennials to reseed should not use corn
gluten until after the seedlings are up and have true leaves.
Effectiveness
Corn
gluten works on seeds not established plants. It will not kill a dandelion plant.
It
has reduced crabgrass by 86% the first year and 98% the second year provided
recommended rates are applied in both spring and fall. Dandelion infestations were reduced 100% in plots treated for 4 years
in spring and fall.
Plants
tested to date for susceptibility = 23 and include: barnyard grass, smooth
crabgrass, curly dock, green & yellow, black nightshade, orchard grass,
shattercane, purslane, wooly cupgrass, giant foxtail, lambsquarters, buckhorn,
quackgrass, velvetleaf, annual bluegrass, dandelions, creeping bentgrass,
black medic, redroot pigweed, catchweed bedstraw, & other common garden
weeds.
Corn
gluten lasts 5-6 weeks. There is no carryover. After
this time seeds can be planted in treated areas without being effected.
How to Use
Application
rate is 20 lbs /1000 sq ft.
Timing
is critical!! Apply in early spring, 3-5 weeks before weeds sprout
(when crocus and early daffodils bloom). 
And
in early fall when temp turns cooler. Apply
in gardens any time.
Spread
around bedding plants, transplants, flowers or shrubs and rake in lightly.
Spread
evenly on lawns. Avoid any bare
spots where reseeding grass.
Sprinkle
on cracks in driveways and sidewalks.
Water
in if there is no rain.
Then
allow area to dry for 2-3 days. Plants
need dryness for corn gluten to effectively kill emerging weeds. If excessive rains occur, reapplication may be needed.
Questions
Is
Genetically Modified (GMO) corn used to make corn gluten?
Up
to 60% of the commercial corn and soybeans in the United States is grown from
GMO Seed. Corn gluten sold as a
preemergent herbicide may indeed contain GMO corn, but it has not yet been
tested. Here's the twist. Corn gluten can reduce the need for traditional herbicides that have
environmental side effects. It likely
now contains GMO corn. It could be
produced from non-GMO corn, but would likely be more expensive.
If
GMO corn is used, can certified organic growers use it and will European markets
allow it? How do home gardeners feel? And
if plants are grown in soil treated with GMO corn gluten, could a crop pick up
anything that show a positive GMO detect in testing?
Will
the 10% nitrogen of corn gluten be a problem for low nitrogen needing plants?
Beans,
peas and other legumes have reduced yields if given too much nitrogen. Also lean-loving flowers such as butterflyweed or coneflowers may not
like the extra nitrogen?
– Kathy Powell, Portage
Co. MG., is excited
about trying corn gluten. She plans
to experiment with it at home in pathways, vegetable and flower gardens as well
as at work in berms that have a large seed bank of weeds.
References:
Presentation by Dr. Nick
Christians, ISU, at 2000 UW Extension MG Conference, Ames, IA
Information from Dr.
Nick Christians' web site, click on Nick Christians.
Necessary Organic, Concern
Natural Garden Products, Weed Prevention Plus. Also conversation with company about their product
Additional Information:
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