Originally Posted by Smallaxe
That comment was a notion used for trees and shrubs,,, years ago... it really wasn't a good mental image for thinking below the soil level even then,,, but certainly doesn't apply to grasses whatsoever...
Grass roots go where the food and water is... in fact many lawns have so much food and water sitting on the surface that roots actually grow UP... It's called Thatch...
I was taught that proper watering is what made for a deep root system on turf?