A "hack" for the perfect, weed-free lawn
Fortunately there's a food we're all familiar with that can help us out. It's corn!
All you have to do is dump frozen corn all over your lawn to prevent weeds. That was a joke. Seriously, don't do that.
There is actually some truth to the joke because corn is competitive by nature. Corn plants use something we call "allelopathy" to outcompete other plants that are growing nearby. (You can read more about allelopathy here on my blog Do Sunflowers Use Chemical Warfare?)
We can harness corn's natural ability by applying CORN GLUTEN MEAL, a protein byproduct of corn processing, to lawns in early fall when the cool season weeds are beginning to emerge.
This also works in the early spring for preventing warm season weeds.
How does it work?
As seeds sprout, they attempt to put down roots and corn gluten meal inhibits the growth of those newly developing roots, killing the vulnerable seedlings as they sprout. Without roots, the seedling can't soak up water, thereby causing it to wither away.
Because corn gluten doesn't know the difference between a weed seed and other types of seeds, it's important to exercise caution while applying it.
Corn gluten meal will not negatively affect established plants with deep roots, like your lawn, since it is only applied to the surface of the soil, but it will work just as effectively on freshly planted grass seeds and vegetable garden seedlings as it does on weed seeds, so if you're planning to seed your lawn or start a vegetable garden, be sure to apply corn gluten meal at least 6 weeks in advance, or wait to apply it after your new grass or vegetable plants are well established.
For best results
If you're using Green It Organic Weed Preventer, water is part of the application, so there are no additional steps needed, but again, do not water the area again for 7 days.
Applying water within the first 7 days can dilute the corn gluten in the soil enough to make it ineffective. This dry period is an essential part of killing those sprouting weed seedlings.
Studies have shown that higher concentrations of corn gluten meal are more effective than lower concentrations, so be sure to follow the application recommendations and don't be tempted to skimp on the application.
20 lbs per 1000 SF is generally the recommended application rate which yields the best results.
When to apply
Timing is critical when using corn gluten meal to prevent weeds. In order to get the best results, it must be applied the week that weed seeds are emerging. Applying too late means that weed seedlings won't be affected, but applying too early means the corn gluten will wash out of the soil before it has had a chance to work.
Other benefits of corn gluten meal
Having a thick, healthy lawn is the best defense when it comes to winning the battle against weeds, and corn gluten meal helps with this as well. Most corn gluten meal is around 10% nitrogen, which is considered very high for an organic fertilizer, and this boost of nitrogen helps the top part of your lawn grow, essentially choking out the competition, weeds.
While Corn Gluten Meal doesn't prevent every weed in every place -- no herbicide does -- the benefits of this weed preventer which doubles as a fertilizer make it a top choice for organic gardeners.