I live in California but I have a property in Northern Italy with many plants. In August, 3 well established pino picea glauca conica went brown and died in a short time . Now I have several lavender showing dark spots on the leaves. Then entire branches dye and eventually the entire plant dies. The weather has been particularly wet in May followed by very hot weather in June, July. Among the possible diseases I found the following all related to excessive watering/poor drainage:

1) Alfa mosaic virus
2) Lavander shab disease
3) Phytophtora

I was wondering if by looking at the picture you can suggest the most likely cause and course of action. For the Phytophtora I was suggested to use Fosetyl Aluminium, but I am wondering if I am wasting time and money