Dave Adams wrote:

We have a Santa Rosa plum tree in our backyard that has always given a bumper
crop of fat, juicy plums. This year, there's only like 3 on the whole tree.
I've done nothing different than usual regarding pruning, fertilizing, etc.

Anybody have similar problems, or even heard of it? What could cause this?

I'm in Marin county, CA

Thanks

Did the tree have a full load of flowers this spring? I'm wondering if
the problem was a lack of flower buds or a problem that prevented fruit
set after a normal flowering.
My plum trees have few flowers this year (mine are in bloom right now).
I live where it almost always goes to 30 below zero or colder in the
winter. Obviously I have to choose varieties carefully if I even expect
the trees to live. After a harder that normal winter I often get no crop
at all.
I don't know how much cold a Santa Rosa plum can take but we know it's a
lot more tender than what I grow. Can we rule out a colder than normal
winter in Marin county damaging the flower buds? (I'm guessing that we can.)

Steve