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How to Kill Grass Before Tilling

By S.F. Heron ; Updated September 21, 2017
Herbicides can be used to kill grass before tilling.

Creating a new garden bed requires the removal of the existing grassy areas before planting. Grass removal using a glyphosate herbicide such as Roundup or manual methods involves time and effort to achieve good results. Tilling soil to prepare for garden installation requires you to turn over existing soil to create the optimum planting environment for new plants. Killing grass is an integral step in eliminating future emergence of grass in the garden bed.

Mow the grass at the lowest setting on the lawn mower. Wait at least three to four days after mowing to allow the grass to begin active growth before you apply herbicide.

Choose a day with no wind during a time when the grass is in an active growth phase. Make sure it won't rain for at least two days after application of the herbicide. Wear gloves, goggles and a mask to limit exposure to the chemicals in the herbicide.

Mark off the grass, using twine secured to stakes, to delineate the area requiring application of the herbicide. Use a hammer to pound the stakes into the ground. Plan to leave the twine in place to mark the area and limit traffic over the dying grass.

Select either the spray or the stream pattern on the nozzle of the herbicide sprayer. Apply the spray as recommended on the label of the product. Spray close to the grass at a height of 6 to 8 inches to avoid overspray onto other areas. It's not necessary to completely saturate the ground with the herbicide. Blades of grass should be dampened with the product, which will seep down to the roots over time.

Remove protective clothing and gloves after application. Wash your hands thoroughly to avoid having any chemical come in contact with your skin or eyes. If necessary, launder your clothing and gloves to remove traces of the herbicide.

Allow the product to remain on the grass for 10 to 14 days. Browning of the grass should appear within 3 to 5 days. Wait a week before reapplication in areas where the grass isn’t responding to treatment.

Till the area approximately two weeks after the final application of herbicide.


Things You Will Need

  • Lawn mower
  • Gloves
  • Goggles
  • Mask
  • Twine
  • Stakes
  • Hammer
  • Glyphosate herbicide in sprayer (Roundup)


  • If you do not want to use a chemical herbicide to kill the grass, you can remove turf manually using a sod removal machine or a spade. Doing so will not kill the grass; you can move the sod to other areas of your yard, where the relocated grass will continue to grow.


  • Chemical grass and weed killers carry risk with use. Carefully read labeling and follow instructions for the best results. These chemicals have been known to alter the microbial balance in soils and can be harmful to small animals and insects. The chemicals are extremely toxic to humans and should be used with care.