"What are the roots that clutch..."

I don't do much yardwork anymore, but I learned how to do all that stuff under the tutelage of my father, and those lessons learned stick with me yet today. 

You don't have to be a tree surgeon to understand how things work out in the yard. Take mulch.  The goal is to provide a bowl for the tree to hold water and keep nutrients in place. Using organic mulch (bark mulch, wood chips, leaves, and so forth...even pine needles) is the only way to go. It helps the tree to retain moisture (especially important in summer!), keeps the soil from washing away,  improves the soil as it decomposes, and keeps the soil temperature more consistent by insulating the ground against cold and heat.

And not mulching properly leads to disease and decay from moisture retention on the trunk, insect damage, rodent damage, too much dampness for the roots (just as bad as too little), and this: if the roots do not develop what they call a normal "root flare," the tree will be unstable and more prone to falling in a storm.

The rule is to form a donut of mulch...and the mulch is not supposed to be touching the trunk! A lot of people go by the  “3x3x3 rule”: 3 inches of mulch, 3 inches from the trunk, in a circle 3 feet wide.

And that leads us to the worst mulch sin of all: piling it up against the trunk. The dreaded "volcano mulch" is quick and easy (and bad for the trees), but you see it in shopping center parking lots, apartment complex common areas, and other areas where a quick and dirty job fills the bill. So avoid this: 

and go for this!

Thank you very mulch.