But they are also used in the production of fertilizer, garden mulch, and soil conditioner.

NPR: Texas Cotton: 'Farmer Profits at Every Step'

Companions or beneficial plants are included to attract insects for natural pest management while some plants are soil amenders providing nitrogen and mulch.

FORBES: Written by Matt Hickman

Two to three inches of mulch spread around plants, trees and shrubs will slow water evaporation from the soil, help cool root systems and inhibit weeds.

CNN: X-rated yards save the environment