Q.Root Systems
Escallonia almost destroyed last winter (3rd time in 10 yrs). Wish to replace it with a box hedge. Have cut down to base of trunk but do want not to remove roots with digger. What is best way to kill off roots so that I can plant bare rooted box in Oct.?

Unfortunately if you hope to replant the area you will need to remove the root system of the Escallonia.
This will insure the best success with your new plantings.
Here is a link with more information.
https://www.gardeningknowhow.com/plant-problems/environmental/planting-in-old-spaces.htm