Question
Jim
I planted a northwest poplar in my back yard and a row of tower poplars in the front as a windbreak.
Two questions:
The front grass used to be lush now it is dry and thin-do you think the tower poplars are to blame?
The northwest in the back is not causing a problem,but keeps sending up suckers from the lawn.
If I were to leave one instead of mowing it,would it grow into a good size tree,or just a small one? Thanks!

Answer
No I would not think the tower poplars directly are to blame for the dry grass. Some grasses do not do well in shade and this could be the case for the grass under the trees but not generally in the lawn.
The sprouts will if let grow become a tree but will have the same root system as it parent. It should be the same height as the other poplars when it reaches the same age. Because the root system is well developed you can expect faster growth than the original planted trees and soon will catch up with them.