One reason we can't just blast in with Roundup is that some of the trees are virtually invisible. Here you can see the base of a fair-sized cypress tree next to the hook knife.

 

 

 

 

 

 

 

 

 

 

 

 

Looking on the surface of the grass I could not see any sign of the tree below, other than a slight mound. The mound felt firm, which is why I looked under it.