How/when to try Corn Gluten Meal for sticky burrs?

10 years ago

Hi, friends! I received great advice on this forum to try Corn Gluten Meal as a pre-emergent sticky burr solution last year. I am very determined to try this because the sticky burrs are basically the majority of the lawn in many places (meaning pulling is not a viable option) and we have small kids and prefer to avoid chemicals.

I was told that there is a small window within which I have to apply the CGM, which corresponds to a forsythia tree blooming sometime around February! I have no idea where to find out whether this tree has bloomed (I don't have access to one!) so I wanted to ask the wise gardeners here for any advice. Is there a website which tracks this tree? Or any specific dates I should look at? I hope I'm not too late!

And once I determine the dates: do I need any tools to spread this CGM? Or just buy in large quantity at Home Depot and sprinkle all around? Or hire a gardener who knows what s/he is doing?

Thank you so much for any suggestions and tips!

Featured Answer

gardengal48 (PNW Z8/9)

10 years ago

First, where are you located? Second. CGM is a pre-emergent herbicide and will only be effective on newly emerging burrs germinating from seed - any existing plants must be killed off before the CGM application or the problem will promptly return. This means you either have to dig them all out by hand or apply some sort of herbicide that targets these weeds, like Weed-B-Gon.

Your window of opportunity is really only controlled by the timing of the life cycle of the burrs - they are annual weeds that tend to be most prevalent in their seeding in spring and fall. The CGM needs soil temps of about 50F to be effective. In many parts of the country, that soil temp coinciding with the blooming of forsythia is just not gonna happen :-) That's the primary reason we need to know where you are located - grass burrs tend to be most common in warm weather climates (Texas, OK. the southeast, etc.) and generally right around the early part of March is a good time to apply to the CGM.

FWIW, grass burrs proliferate when the lawn is in poor condition. Improve the health of your lawn with aeration, applications of organic matter, over-seeding and proper mowing and irrigation and the lawn will outcompete the burrs.

Sort by:Oldest

Comments (6)

Polina
Original Author
10 years ago
Thank you so much! I am in Mountain View, California (SF Bay Area).

I dug out a LOT of the weed last year but there are such an overwhelming quantity that it would essentially be ripping out most of the lawn, plant by plant! The level of control I have with regard to the lawn is limited because I am a renter, or I would probably attempt some kind of more serious overhaul, but I am trying to find the best approach given the limitations! Do you think that using CGM every year along with pulling (but probably never getting it all pulled out) will not make much difference?
Related Professionals
Ocala Landscape Architects & Landscape Designers · Fort Worth Landscape Architects & Landscape Designers · San Antonio Landscape Architects & Landscape Designers · Charlottesville Landscape Architects & Landscape Designers · Lawrence Landscape Architects & Landscape Designers · Pittsburg Landscape Contractors · Dayton Landscape Contractors · Huntington Landscape Contractors · Winona Landscape Contractors · Morgantown Architects & Building Designers · Mason City Architects & Building Designers · Williamsport Architects & Building Designers · Lewiston Architects & Building Designers · Spokane Architects & Building Designers · Leamington Architects & Building Designers
kimmq
10 years ago
Corn Gluten Meal needs to be applied about 6 weeks before the unwanted plant is to germinate, for most of these that is about the time the Forsythias blossom. Corn Gluten Meal dos not stop seeds from germinating but does inhibit the development of the plants roots.

kimmq is kimmsr
Polina
Original Author
10 years ago
Thanks, kimmq! Yes, as I mention in my post, I can't figure out how to determine whether the Forsythia tree/plant has blossomed or not! Any further info would be much appreciated!
kimmq
10 years ago
Talk with some knowledgeable folk at your neighborhood nursery about when Forsythia blossoms in your area. Around here (West Michigan) that is April, but I can find nothing worthwhile on the internet for your area.

kimmq is kimmsr
gardengal48 (PNW Z8/9)
10 years ago
Forsythia is not a very common plant in the Bay area and other parts of CA, so I doubt using that as your guide is going to be much help. In my area (a pretty similar climate), forsythia blooms in mid to late February in most years, so I would target your CGM application for mid-February to the beginning of March.

Be advised that UCDavis (the CA extension service sponsor) does not necessarily endorse CGM for effective weed control: "Research conducted in the Midwest suggests that repeated
applications of corn gluten meal may prevent the emergence of
some weeds, but the research results are not consistent. In
experiments conducted in California lawns, corn gluten meal
did not provide satisfactory control. One hypothesis about why
corn gluten meal may appear to help in weed management is
that its high nitrogen content acts as a fertilizer, making the
turfgrass more competitive with weeds. Corn gluten meal
has no effect on already emerged weeds. It is also significantly
more expensive than other registered preemergent products
known to be effective."