You can rid yourself of weeds the old fashioned way—pulling them by hand—if you’re vigilant. Wear a dedicated pair of gardening gloves for the task to avoid inadvertently transferring seeds elsewhere. Good gardening tools like a claw or sharp trowel can help you loosen the weed roots from the soil first. Pulling a weed completely out by the root is the only way to ensure it will not return.
Cover your planting areas with mulch and you’ll keep weed seeds from coming into contact with the soil in the first place. Mulch will also keep sunlight from reaching seeds that are already underground, so they won’t get a chance to sprout. Mulch offers the added benefits of retaining moisture and breaking down to enrich your soil. And it looks really pretty, too.
Did you know that corn gluten meal is birth control for seeds? Sprinkle it on your garden and it will keep weed seeds from germinating and growing into plants. Of course, corn gluten meal will keep any seed from germinating, so don’t try this on your vegetable garden until your plants are established and you’ve finished planting seeds.
Smother weeds and prevent new ones from growing by covering them with old newspapers. A thick layer of newspaper will keep sunlight from reaching weed seeds, so they can’t sprout. Wet the soil first, and then lay your newspaper down, wetting it thoroughly again before covering with mulch. This is a great way to recycle, and as a bonus, you’ll encourage earth worms to come and stay.
Apply vinegar with a spray bottle, pump sprayer, or brush. Like other natural herbicides, vinegar cannot differentiate between weeds and other plants. Do this early in the morning, when there’s little wind, to avoid contaminating nearby plants. Vinegar’s killing properties are activated by the sun, so try this on a cloudless day, which also ensures that rain won’t wash it off before it works its magic.
“I began to measure weed seed predation and saw that within two days, nearly all of the seeds I’d put out in the field [to measure the amount of weed seed predation] would be gone,” says Davis, an ecologist with USDA’s Agricultural Research Service at the University of Illinois. “Over the course of a growing season, I’ve seen weed seed predators eat between 40% and 90% of the seeds produced that year. It’s an important weed management benefit that we take for granted, but which really makes a difference.”
Davis conducted that early research to evaluate a valuable option for growers who want to manage hard-to-control weed populations: Manage the weed seedbank to prevent weeds from getting started.
Weed management toolbox
As a graduate student, Adam Davis spent his Septembers crawling around on his hands and knees through crop fields trying to find and recover giant foxtail seeds for his research studies. He soon discovered that seed predators had already eaten the seeds on the soil surface. Mice, crickets, ground beetles and other organisms were doing a highly effective job at reducing the number of weed seeds.
“We focus on killing weed seedlings because we can see them, and we have products available to do this,” Davis says. “Certainly, we don’t want to give up managing weed seedlings, but if we reduce weed seedbank population densities, managing weed seedlings becomes much easier.”
The key to weed seedbank management is to reduce the ability of the seeds to germinate. Then growers either don’t have the weeds to control or they have fewer weeds to handle with other weed management tools. Here are Davis’s suggestions for managing a seedbank: