CORVALLIS — Grass lawns are the default for most yards, but some people have explored other options, such as edible landscaping, a bark-dust yard or low-maintenance groundcover.
"Maybe you have a lawn full of difficult-to-control weeds like annual bluegrass or rough bluegrass and you want to start over," said Alec Kowalewski, turfgrass specialist with the Oregon State University Extension Service. "Or you want to switch from grass to lawn alternatives like groundcovers."
In either case, you'll need to first remove the existing grass. Kowalewski offers two main approaches: an organic technique that uses no pesticides and a chemical method that employs an herbicide that leaves no residue in the soil.
The organic method begins with placing plastic sheeting on top of the grass. "You need something that will totally stop the gas exchange of the atmosphere," Kowalewski said. "You're essentially suffocating the plant." In the heat of summer, it could take two to three weeks to kill the grass.
The conventional method is to spray a non-selective herbicide, such as glyphosate, on the grass in early morning and away from other plants. Apply again two weeks later to kill any dormant weed seeds that may have germinated. When applying pesticides, always wear protective clothing and follow the instructions on the pesticide label carefully.
Regardless of which method you choose, Kowalewski recommends scalping down the dead grass with a mower when it turns brown and then aerating the lawn.
Because living root parts might still remain underground, it's wise to completely remove any sod, as well. A hand- or gas-powered sod cutter can be rented to separate the sod from the soil. Adjust the blade depth one-half to one-quarter inch. Afterward rake up sod manually with a square shovel or pitchfork.
Throw discarded sod and grass in the garbage or compost it. Because glyphosate breaks down quickly, it should be safe to add sprayed grass clippings to compost, said Kowalewski.
With the old turfgrass successfully removed, you're ready to establish your new landscape.
To learn more, see the Extension guides:
- "Practical Lawn Establishment and Renovation" at http://bit.ly/OSU_LawnBegin
- "Turfgrass Seeding Recommendations for the Pacific Northwest" at http://bit.ly/OSU_TurfTypes
- "Plant Selection for Sustainable Landscapes" at http://bit.ly/OSU_LandscapeSelection