Christmas tree and conifer cover crops.

[dreambig@84]

Whats the best way to maintain a new conifer planting for optimal growth and weed control?
I currently use round up and stinger around trees to control weeds but should I plant grass or green strip around them or near them to help control other woody plants from growing in so I can mow between rows? I don't want to plant clover to attract deer near my trees and access path since it's a screen I'm trying to establish

 

[Hardwood11]

I use a weed mat and cage the tree . We then mow the area of the planting .