Controlling Weeds before You Plant Your Lawn
If you have decided that you are ready for a total lawn makeover, your first order of business should be to get rid of the weeds. Most professional landscapers will tell you that the best way to get rid of weeds is to spray the entire area with an herbicide.
The most commonly available, easiest to use, and relatively safest herbicide is one with the active ingredient glyphosate. Brand names include Roundup, Kleenup, and others. The best way to tell whether you’re getting the product you want is to ask your hardware store or garden center associate to help you. Be sure to read the label and look for the active ingredient glyphosate.
You will probably have to apply this herbicide more than once.
For a lawn over 1,000 square feet, you need to rent or buy a backpack sprayer to do the job. The herbicide comes in a concentrated form that you mix with water according to the manufacturer’s instructions.
Cordon off your lawn with tape, streamers, balloons, or some type of barrier. Keep the kids and your pets off the lawn and away from the yard. Glyphosate is a relatively benign herbicide, but it is a pesticide, and children and pets have lower sensitivity thresholds to chemicals than adults.
Make sure that you follow the label instructions and wear a long-sleeved shirt, long pants, rubber boots, and plastic gloves. Wait the specified time for the herbicide to work and then rake off any debris. Your lawn should be grass- and weed-free at this time, but be sure to make another application if you feel it is necessary.
When you’ve finally decided that all weeds and remaining grass are gone, wait one week before you plant your new expensive grass seed.
For those of you who prefer not to use toxic synthetic chemicals to kill the old grass and/or weeds, you can take several approaches to getting rid of weeds without chemicals.
Rent a tiller: For a modest-sized yard with not a lot of weeds or dense turf, till your lawn area to a depth of 4 to 8 inches, rake out the grass and weeds, and till again. Keep tilling and raking until all the green matter is gone. Dump all this material in your compost bin where it decomposes over a period of months.Credit: "Horns & Tiller," © 2008 , Lisa Brewster used under a Creative Commons Attribution 2.0 Generic license: http://creativecommons.org/licenses/by/2.0/legalcode
Be sure to get a tiller that has the rotating tines in the rear behind the tires. They easier to handle than the tillers with the tines in front and over the engine. Running a front-tined tiller is like trying to control a bucking bronco.
Don’t try to till dry or very wet soil. Water the whole area, let it dry for a few days, and then till.
Renting a sod cutter: You simply guide the sod cutter over your old weedy lawn, and it cuts the turf at just below soil level. Turn the sheets of grass upside down where they will decompose and add nutrients to the soil. You also can haul the sod to a recycling center that accepts yard waste.
Using black plastic: If your lawn is less than 1,000 square feet, buy enough heavy-gauge black plastic to cover your entire lawn. Spread the plastic out over the lawn and weigh down the edges with stakes, or rocks. Without sunlight, grass can’t grow and eventually dies. This process can take anywhere from a month to three months, depending on how hot and dry your season is.
Plowing: Plowing is another method to use if your lawn is rather large. Adjust the plow blade or blades to dig the soil to a depth of 6 to 8 inches. Rake off the weeds and debris and keep plowing and raking until you get rid of all the unwanted green matter.
*Bulldozing: If you have a really large area, a bulldozer or Bobcat may be a good option. Adjust the blade so that you’re just scraping off the thin layer of grass and weeds. You don’t want to take off the soil layer.