Here's a breakdown:

* Loamy soil: A type of soil that has a good balance of sand, silt, and clay. It's known for its good drainage and ability to retain moisture and nutrients.

* Gravel: Small rocks, typically less than 2 inches in diameter.

Adding gravel to loam provides several benefits:

* Improved drainage: Gravel helps to prevent waterlogging by creating air pockets within the soil.

* Better aeration: The spaces between the gravel allow for better air circulation, promoting healthy root growth.

* Increased warmth: Gravel can absorb heat from the sun and radiate it back into the soil, making it warmer for plants.

* Nutrient retention: Gravel can help to hold onto nutrients in the soil, reducing leaching.

However, too much gravel can make the soil too dry and difficult for plants to access nutrients.

Overall, a mix of rich soil and small rocks can create a well-draining, airy, and nutrient-rich environment that is ideal for many plants.