I planted a jasmine (polyanthum I think) in our backyard last spring. It is positioned in a corner where it gets 2-3 hours of sun on a sunny summer day, but this being the Netherlands, that remains only a theoretical possibility most of the time.
We had a cold spring last year, and the plant was initially stunned by the cold, as I forgot to acclimate it. But then it started to grow spectacularly and is now about 2.5m high. I fed it through the growth season two or three times with a balanced fertilizer.
Since mid-autumn this year, some of the leaves in a waist-high section started going gray. I somehow assumed that since it was the end of season it was going to shed its leaves, but it hasn’t. The gray/black leaf issue continued spreading, though, and it increasingly looks like a disease (see photos).
I can’t figure out what the problem is just by looking at the photos online. Cold? Fungal disease? Root rot? Blight? Malnutrition? Overwatering? And does this problem need a remedy, or should I just wait for the spring to come?