WHAT WOULD I USE TO KILL IT.NOT WANTING TO HARM MONKEY PUZZLE TREE
I would rake it out with a springbox rake and fork the soil too to allow air and water to penetrate..
Add some horticultural sand over the area and brush in,
The moss dislikes the sand content and this will help keep the area dry, as damp compacted soil encourages moss.
Springbok rake that should say.