I live in South India .We bought this yellow rose 4 years ago, which blooms and slowly turns white in color after few days.[Since I don't know which variety it is] Earlier,we planted the shrub beside and Allamanda blanchetti tree,the Allamanda overtook the rose in growth and overshadowed it.So we decided to shift the rose for its better growth.
We looked up tutorials online on how to transplant grown rose shrubs and followed their instructions.
The transplantation went well and around 1 week tiny leaves started to appear. It was raining heavily around that time ,and after 3 more weeks leaves were well grown,then I put a bit of wood ash and some cow dung around the plant.[the soils in our region are not very fertile]
All was going well for next 1 week or so,and the rain continued intermittently.Then I noticed that some of the older thick branches[which we had not pruned during transplanting were turning black and leaves on it started to turn brown ad die] This spread to other branches and we didn't add anything to the plant during this time[raining in torrents]
Now the plant has just one branch left with few leaves and a tiny green shoot.
Note that there wasn't any rose plant earlier in the spot we transplanted it.
What is the reason for the branches to turn black and die?
Are there any ways to revive the plant back to health?