How to get rid of underground tree roots

Question

We had a huge cottonwood tree removed from back yard. Now about 100 more are coming up from the underground root system. Is there some way to kill the roots, short of having to dig up the whole yard? I've tried spraying the new trees with roundup, it does kill that little tree, but 15 more sprout up.

Answer 1

About all you can do is keep mowing them down.

Unless like you said you dig up the whole yard.

Usually the roots run out of food in a year or two and quit sending up suckers.

If you cut the sucker and its section of root out of the ground it helps sometimes.

It is important not to let them leaf out or they start feeding the old roots to produce more suckers.

Oh yes. one more thing.

Round-up and 2-4D are actually growth hormones and will promote suckers forming as the hormone spreads through the root system.

Both of these poisons work by driving the plant to over grow its resources.