Question
My property has been thinned of some scrub oak and the spray used on the stumps did not work.  Live and cut trees are still sending out root runners everywhere.  How do I get rid of the root runners short of repeatedly digging them up on an acre of ground.  Thank you.

Answer
I assume you are talking about sprouts from the roots not new roots growing. A herbicide called Roundup will kill the new sprouts but you need to be careful with Roundup it will kill any green plant it gets on. Care should be taken to not spray any plant not wanting killed. Instead of spraying the Roundup can be wiped on the foliage of the sprouts without getting on adjacent plants. If this is in a lawn situation mowing will kill the sprouts--The roots will continue sprouting until they run out of energy (food stored in the roots). Without the green sprouts the roots can not store food and will not survive and will die.