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how to remove weed seeds from soil

Run a mower over the land to reduce the weeds’ height further. Now that all the weeds are as short as possible and the stumps have been removed, rent a large tiller to uproot all the weeds. Since this plot of ground is uncultivated soil, you will need a tiller that has some power: Do not undertake this task with a small garden cultivator! Allow the tiller’s tines to dig deep enough into the ground to loosen the weeds, so they can be removed—roots and all, if possible.

Soil solarization is a preventive, organic method of killing weeds before weed seeds even sprout.   But the advice below is also meant for homeowners wishing to start a garden with a clean slate, reclaiming a patch of land where weeds have taken over, in such a way as to reduce to a minimum the hassle of future ​weed control. Want to transform a piece of land that has “gone to pot” into usable space? Then the method explained below may be the solution to your problems.

Preparation

There is lots of work involved since soil solarization entails getting to the root of the problem, underground.   And we will not be taking the shortcut of using herbicides, so that means a bit more work. But if you do not mind getting your hands dirty, then let’s roll up our sleeves and begin stopping our weedy foes in their tracks.​

Now use a steel rake on the area that you have just tilled, wielding it like a fine-toothed comb to remove the majority of the uprooted weeds. Next, rake the area again, this time with the object of evening out the soil as best you can and removing stones, twigs, etc. The final preparation for soil solarization will require the use of a garden hose. According to the University of Idaho Extension (UIE), you should moisten the area that you have just raked to “conduct and hold heat, to stimulate weed seed germination, and to prevent dormancy of below-ground vegetative plant parts.”

When you cut slits in the landscape fabric and install new plants, be careful that you don’t get dirt all over the landscape fabric. After all, why prepare a home for airborne seeds? Sure, you will be applying mulch. But airborne weed seeds can wend their way through mulch particles. If they find dirt, then they are “weeds waiting to happen.”

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.

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.

Cornmeal

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.

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.

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.

“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.”

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:

Weed management toolbox

Cover crops can be a tool for weed seedbank management. “Cover crops have had a long history in the Midwest, and can make a comeback should market forces and weed management realities combine to make them necessary,” Davis says. “Adding cover crops to the weed management toolkit can reduce opportunities for weed seedlings to establish, and can also provide a critical delay in weed seedling emergence so that crop competition can further suppress weeds.”

Davis says the most important element of a successful weed seedbank management strategy is to implement a diversified crop rotation so crops with contrasting life histories are grown in different phases of the rotation. “This prevents any one weed species from getting too comfortable, and makes it difficult for weeds to reproduce in the canopy of a crop with a different life history,” he says.

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.