Water the soil to moisten it, but don’t add so much that the ground is saturated. Add water until it soaks in to a depth of 1 inch.
Cover the ground with sheets of builders-grade clear plastic. Bury the edges of the plastic in the ground or hold them down with bricks, rocks, cinder blocks or other heavy debris. Overlap the edges of the plastic by about 3 inches to make sure the entire plot is covered.
Water the plot of land to force any seeds in the ground to sprout,, advises the University of California Agriculture & Natural Resources. Allow them to grow for a week to make sure as many sprout as possible.
Mow the lot with a lawnmower set at 1 inch. This will remove the majority of the plant material above ground. Use a mower with a bag or rake and remove the mown plant debris.
Dig down 6 inches over the entire plot of land and turn over the soil. Remove any large rocks or roots you find and break up large clumps of dirt. Smooth the soil with the shovel to make it roughly level.
Just as a great painting begins with a blank canvas, a great sod lawn starts on a plot of land without weeds. Laying sod on top of weedy soil, even soil that has the weeds plowed under, is asking for trouble. Weed seeds will survive underground and sprout through your freshly laid sod, ruining that perfect swath of green you’re attempting to create. Rid your soil of weeds and weed seeds before laying sod, and you’ll have better results in the coming seasons. You’ll increase the curb appeal of your home while cutting down on weeding chores.
Leave the plastic in place for four to six weeks. The heat from the sun will create a greenhouse effect underneath the plastic, heating the soil enough to bake and kill any weed seeds that exist underground. Remove the plastic after six weeks and lay the sod.
Also, do not apply pre-emergent on new sod until at least the following growing season. These types of herbicides can severely limit your sod’s growth if applied too early.
The trick to getting rid of weeds before laying sod lies in the preparation. In order to fully eradicate weeds that can otherwise invade your new sod lawn, you need to follow these steps:
To get rid of weeds before laying sod, you should first apply a natural or chemical weed and grass killer to kill all existing weeds. Then, use a sod cutter to remove the old lawn and weeds. Finally, till the lawn, water it, and wait 1-2 weeks. This step is essential because it will cause any weed seeds to sprout. Treat these with a weed killer or herbicide to fully stomp out the invasion. Then, you’ll be ready to lay new sod with confidence that weeds will not return.
You can also use Atrazine for certain broadleaf weeds, or a 2,4-D weed killer, but consider the best option for your old lawn. For example, if you currently have Bermuda grass, 2,4-D will preserve most Bermuda, while Atrazine will kill it.
Can You Lay Sod Over Weeds?
Use a sod-cutter tool to remove your old sod layer. Sod cutters are available for rental at most hardware stores and are essential in the process of sod installation on a new lawn. If you don’t remove the old sod there is a huge potential for weeds and grasses to grow through your new sod. Removing your existing sod helps get rid of weed seeds, rootstock, rhizomes, crabgrass, and other dead grass.
Alternatively, if your yard is small, you can cover the grass with black plastic to block sunlight and moisture from the soil. This should kill weeds within 4 weeks, and prevent even a single weed seed from growing, but can be inefficient as it is slower than weed killer, unsightly, and not practical for large yards.
When you are preparing to re-sod your lawn, unless you’re laying sod next to existing grass, you can attack weeds and existing grass with a no-holds-barred approach. You want to kill all existing weeds and grass, so you can use strong weed killers that act fast.
Time to Sod
The purpose of laying grass sod is to start new, with a fresh carpet of healthy, weed-free grass. Your beautiful fresh sod can be destroyed by old weeds and invasive grasses pushing up through the new grass, and all your time and effort sodding will seem wasted. The best way to prevent this fate, and ensure your new sod takes root, is to get rid of existing weeds before you lay down sod. To do so, follow these steps:
Whether you choose Glyphosate or vinegar-based weed killers, use a pump or backpack sprayer to spray the lawn. Then, wait a week to allow the weed killer to fully kill any and all weeds.