I have a lonicera nitida hedge which is 60 years old and was in excellent condition until this year. The entire hedge (about 200 feet) is now withering (I have attached a phot). I think the snow earlier in the year may have caused the problem. I have tried treating the headge with Miracle Grow compost and Grow More fertiliser but to no avail. If you have any suggestions as to what I could do to try to revive it.
Kill the grass with Roundup for 60 or 100cms to reduce root competition. It can be re-sown when the hedge recovers.
Feed the dead area with 20g per metre of tree and shrub fertiliser. You could ease off on clippling and cut out dead bits low down and plant some cuttings in October in the gaps, Lonicera roots easily from cuttings.