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 you truly have a “clean slate” with which to work. Remove the plastic and lay down landscape fabric. You should try to use one of the stronger types of landscape fabric if possible, just in case—in spite of your best efforts—any sharp objects remain in the ground (which would puncture the landscape fabric).
Cover the raked, moistened area with a clear polyethylene sheet. The edges of the sheet can be held down by cinder blocks to keep the plastic from blowing away. If the raking mentioned above was done diligently enough, there will be no sharp objects sticking up to puncture the plastic. The sheet of clear plastic can be anything from 1 to 6 mil. in thickness. In the Northern hemisphere, the best time for soil solarization is June and July, when the sun is at its peak. UIE recommends keeping the sheet of clear plastic tightly stretched out over the area for about 2 months. During that time, the sun will be killing weeds for you—”cooking” them before they have a chance to sprout. Plant pathogens will be killed, to boot.
If there are shrubs and trees present, cut them down with an ax or chainsaw. The ground needs to be smooth before you begin soil solarization (since you will be spreading plastic over it), so you will also have to remove the stumps left behind. If you are looking for a cheap way, use a tool called a “mattock.” Dig and chop your way with the mattock under the root-ball to access and remove the taproot. Warning: this is hard work and may be feasible only for smaller stumps.
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.
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.
“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.”
Weed management toolbox
“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 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.
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.
Excellent info – but please, to be clear, the seed head illustrating #4 is Goldenrod, Not ragweed. There’s a Big difference, primarily that Goldenrod does Not produce Airborne pollen like ragweed does. And although Golden rod can and will get quite weedy, it is also a primary source of nectar for migrating monarch butterflies, so I always make sure I have plenty in my “Every-Man-For-Himself” garden. You know, the one where the tide waxes and wanes annually between the Goldenrod, the Beebalm and the Obedient plant 😉
Beyond these strategies, enriching your soil with organic matter every chance you get can move your garden along down the weed-free path. Soil scientists aren’t sure how it works, but fewer weed seeds germinate in soil that contains fresh infusions of good compost or organic matter. One theory makes elegantly simple sense: When soil is healthy and well fed, weed seeds sense that they are out of a job and are less likely to appear.
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4. Lop off their heads
Few experiences compare to the joy of watching weeds shrivel in the sun after a morning weeding session, but then what should you do with them? Their best resting place, of course, is a compost pile or bin, which is the end of the story if the weeds going in are free of seeds. In reality, however, a good half of the weeds you pull probably hold seeds. Separating the seedies from other weedies is impractical, so weed seeds in compost are customarily killed by raising the temperature in the heap.
If you’re a new gardener—or you’re working in a wild and weedy space—the first season will likely be a rough one. Commit (and stick) to a weeding schedule, and don’t take on more space than you can manage. If you have more weeds than you can handle, keep weedy areas mowed until you’re ready to conquer them.
thanks this was very helpful and had no mention of statues.
Some light passes through chunky mulches, and often you will discover—too late—that the mulch you used was laced with weed seeds. It’s important to replenish the mulch as needed to keep it about 2 inches deep (more than 3 inches deep can deprive soil of oxygen). In any case, you can set weeds way back by covering the soil’s surface with a light-blocking sheet of cardboard, newspaper, or biodegradable fabric and then spreading prettier mulch over it.