Two years on, how is the hedge doing? Well, not terribly well, to be honest. We have neglected it by not feeding it, being slow to remove weeds, and not watering as much as we could during dry spells. (The hedge is on a raised bank, so the last point is rather serious.) Most of the plants are struggling to get above three feet tall (although we have clipped some down to the 4-foot-high protective fencing). There is also very little horizontal growth or inter-meshing, despite our topping the plants prior to sprint growth.
We need to be patient, and more caring for the poor plants, and we may buy a few plants for in-fill where dead plants have left gaps.