Several years ago we bought two Rosa Bansiae (Lady Banks) climbing rose plants in South Carolina and planted them in large planter boxes on our deck in Virginia. They have both thrived until this year, when they did not seem to weather the winter well and there were a lot of dead branches to contend with this spring. We did not prune off the dead until after the spring bloom, as not to stress the plants. One plant looks like it will do well and is giving off a lot of new shoots from its base and other areas. The other is not producing new shoots and some of the leaves on mature branches are turning yellow. What should we do for it? Fertilize? Are we under watering or over watering? There is very good drainage in the planter box and it is very large. There are some tiny black ants that crawl up and down the trunk, but there doesn't appear to be any damage to the foliage, other than it turning yellow. Any ideas on what we should be doing for this/these plants? Thanks!