Yes, I also saw a dearth of plums on my tree after a heavy yield last year. But a wet spring is not the only explanation. Fruiting trees often take a break after a particularly heavy harvest year as they bulk back up after such a great expenditure of energy. I am going to wait and see what happens this summer with my plum tree  so I suggest you do the same. Let us know how it goes, Keep growing, Marianne Binetti