Question
The Ponderosa pine I planted 7 years ago has grown into a beautiful tree. However, over the last year or so some of its large roots (4+ inches in diameter)have appeared on the surface of my lawn. They have disrupted the lawn and grown near our sidewalks and I'm afraid it will break the sidewalk soon if something isn't done. A nursery said these were "anchor roots" and would be okay to cut off. The tree is about 15 ft tall. Won't this kill the tree?
If okay to remove the roots, should it be done by an expert or can I do it (and how is it best done)? Please advise. Thanks  

Answer
Alan,

Contrary to popular belief the roots of a tree do not mirror the above ground canopy.  A trees roots spread out laterally as much as 3 times the diamter of the canopy.  Also 95% of these roots grow in the top 12" of the soil.  The advice you have been given, in my opinion, is wrong.  Cutting these roots will start a process of decline that would last for several years ending in tree death.

Tree roots are parts of the plant where respiration occurs and this involves gas exchange which is why tree roots primarily grow in the top of the soil.

I would not cut these roots and would offer an alternative solution.  I would create a planting bed around the tree and use a bark mulch.  This eliminates the need for mowing.  The sidewalk issue is another matter.  Moving the tree may or may not be a solution you want to entertain.  I would consult a CERTIFIED arborist, not some guy who prunes trees for advice.

Good luck

Gary