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.
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.
Killing Weeds Through Soil Solarization
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.
Now you’re cooking. Easier than solarizing, plug in an old Crock-Pot outdoors, turn it to its lowest setting, and warm batches of compost while you sleep (three hours at 160°F kills most weed seeds).
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.
Monday: Kill weeds. Tuesday: Kill weeds …
Under dry conditions, weeds sliced off just below the soil line promptly shrivel up and die, especially if your hoe has a sharp edge. In mulched beds, use an old steak knife to sever weeds from their roots, then patch any open spaces left in the mulch.
Does 32 ounces of vinegar mixed with 1/4 ounce of soap sound like an accurate mix
1. Let sleeping weeds lie
Keep it hot. Running a hot heap calls for precise mixing and remixing of materials. Rather than struggle to heat up a heap that wants to run cold, I suggest waiting until a weedy heap reaches a nearly rotted state to set things right. From there, you can solarize small batches of moist compost in black plastic nursery liners that are enclosed in clear plastic bags and placed in the sun for two to three days.
Weed control can be handled with short-term or long-term approaches. Short-term management focuses on controlling weeds during the first part of crop growth when weeds are more likely to affect crop yields. Long-term weed management, however, works all season-long to deplete weed seeds from the seedbank (the reservoir of viable weed seeds in the soil). Whichever approach you take, using a stale seed bed is a great cultural weed control technique.
Ah spring! The war against weeds begins anew. The first major skirmish of the growing season should happen before planting. The stale seed bed technique is an often over-looked practice that can be used before planting. It works by first encouraging weeds to sprout and then killing them when they are young and most vulnerable. For organic growers, a stale seed bed can replace the effects of a pre-emergence herbicide. And when used properly, it can contribute to both short-term and long-term weed management.
To use the stale seed bed most effectively, start several weeks before planting. An initial cultivation kills any emerged weeds that have overwintered. It also brings weed seeds to the surface where exposure to light and oxygen stimulate germination. Depending on the weather and types of seeds present in the soil, weeds may sprout up overnight or over a few weeks. When weeds have germinated and are still small and young, they are easy to kill with a second light cultivation. This process is then repeated as needed and as time allows. As few as three cycles of light/ shallow tillage can reduce the number of subsequent weeds noticeably. For fields and gardens with very heavy weed infestations more cycles of repeated tillage over a few years will be needed. Using a stale seed bed may push back your planting date; but in the absence of weed competition, the crop will have more access to water and sunlight and be able to make up for lost time.
Stale Seedbed is most effective when it’s part of a zero weed threshold system.
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