Why Mulch Depth Matters More Than You Think

Mulch works by moderating what happens at the soil surface. A properly applied layer:

• Shields soil from direct sun and heat
• Slows evaporation and keeps moisture consistent
• Reduces weed germination
• Improves soil structure as organic mulch breaks down

But soil also needs oxygen and airflow. When mulch is applied too thickly, especially in fine or compacted materials, it can trap moisture, block air exchange, and stress plant roots. What looks tidy on the surface can quietly undermine plant health below.