Why does crab grass come out in July?

Crabgrass typically emerges in July due to warm temperatures and increased sunlight, which create ideal conditions for its growth. The seeds of crabgrass germinate when soil temperatures consistently reach around 55°F to 60°F, often coinciding with the heat of summer. By July, the combination of warmth and moisture encourages rapid growth, allowing crabgrass to thrive and compete with other plants. Additionally, it often takes advantage of weakened or stressed lawns during this time, further expanding its presence.