How do I kill small tree stumps and roots?

YOu have two options. One is to hire a stump grinder to come out and grind down the stump and the roots. The other option is to use a stump killer. Do not get any of this on your bare hands as you will get quite ill from it. The small amount of money a stump grinder would cost you would be well worth it as you would not be using a poison that could linger in your yard for years on end. Also with the stump grinder method you could immediately plant another tree or bush with no problems.