Increase mowing height to shade out weed seedlings

What to Do

Raise your mowing height to the upper end of the recommended range for your grass type. For cool-season grasses, this means 3.5 to 4 inches; for warm-season types, the top of their range.

Why It Works

Taller grass casts more shade on the soil surface, reducing soil temperature and blocking the sunlight that weed seeds need to germinate. This is one of the simplest, most effective organic weed-control strategies and costs nothing to implement.

Tips

• Raising mowing height by even half an inch can measurably reduce crabgrass germination.
• This pairs well with mulching clippings, which adds another layer of soil coverage.
• Do not raise height above recommended ranges — excessively tall grass flops over and develops disease.