I planted two prune plums supposedly compatible about 3-4 years ago. For the second year in a row, I get blossoms and what looks like fruit set, but while they are still the size of large hat pins, the tiny plums and their stalks turn yellow and fall off at the mere touch of a finger. I haven't yet gotten any plums to stay and ripen on these two trees. They came into bloom during one of our April warm spells which was followed by cold temps and frost. None of the leaves on the plum trees look damaged and I have seen no insect pests or diseases.
Do I have to plant plums in highly protected locations from wind and frost (we do get cold wind in the spring in our PA yard)? I thought they were tough enough for zone 5. Is it a pollination issue?
I really want some plums to set and stay!