About a year ago, our area suffered from a late spring freeze and one that severly impacted the new growth on my holly bushes. I pruned off the dead growth and all seemed fine. However, I noticed many of the remaining branches turning yellow. Before I found out I had a scale infestation, I lost several complete bushes and lots of limbs on others. I finally got the scale under control and trimmed off a lot of dead/diseased limbs. Bottom line: Will the hollies that have some of the yellow leaves recover? Do I need to do a severe pruning to get all of them back in good health?