Trees, Shrubs and Conifers: Pruning advice for my 16 American Elm root sprouts, 3rd year, 5 by tnken

tnken wrote:
I cut down this American Elm tree in the center of my yard in the fall of 2010. In 2011, we didn't mow for an extended period of time and then noticed about 27 root sprouts all across the yard.

Over the next 3 years, some of these sprouts died off, but a few have achieved what is to me, amazing growth. 10 of them are now well over 8 ft tall, with another 6 much smaller but growing.

I'd like as many of these as possible to grow into trees and I think I should be doing something to help manage that growth, like pruning and such. So far, all I've done is clear back grass at the base, add some tree/shrub dirt, and pesticide the leaves.

What concerns me is that at the base, there doesn't always appear to be a "trunk" but a cluster of several branches pointing upward.

Would really appreciate any advice. Thanks in advance!