An ecologically safe and easy to use weed killer is simply water! Just boil it in your teapot and water the troublesome weed with some scalding hot water. It is non-selective so anything it touches it could kill. It’s effective against most weeds but they may need a second treatment. Be sure to target the root and stem area. Just hitting the leaves will only damage the leaves and the plant could come back. This is best used as a spot treatment.