Trachelospermum Jasminoides / Star Jasmine dropping leaves
My Star Jasmine has been fine for the last 3 years. This year however, it has started to drop leaves after turning red then yellow. I have read that this means the plant is stressed.
There are a lot of flowers about to come out so that looks fine. But some of the leaves have this scaly sap sucking creature attached to them - some of them have nothing at all so not sure if this is the problem.
It has also been next to a rhododendron since day one and the fertilizer has never created a problem. It has good drainage even though the roots can be seen at the bottom of the brick wall in the drainage holes. It is planted in a restricted, closed area with other plants and cannot be moved. It could be cramped but I have seen other plants in containers do very well and it has been like this for a few years, so why now?
Given the restricted conditions that it is growing in, what can I do to? Is this scaly creature causing the problem and if so, how do I get rid of it? If I leave it, will it right itself or could the whole plant die?