We in the northeast, had an unusually warm winter and my peaches, plums and cherries were flowering in march. They are 4 year old trees, very hardy, well pruned and healthy. I was building fires at 3AM throughout Late march and april to save the blossoms from the frost. It seems to have worked since my redhaven and elberta peaches are loaded (since thinned).
My plums, on the other hand, seemed to dodge the frost as well. There were hundreds of tiny 1/4 inch green fruits after petal fall. Now, nearly three weeks later, they are turning yellow and falling off the tree. I maintain a rather regimented spray schedule, so I am puzzled as to what happened. There are a few fruits left on the tree that are now 1" size. The variety of the plums are Alderman and Underwood (a shiro relative). This same thing happened last year as well.

Obviously, they are lost this year, but what can I do to achieve a decent crop?
Thanks
Josh

Scott

Same thing with Coe's. Lots of blooms, all the fruitlets fell off.

Green Gage set quite a few plums, as did Kirk's blue.

I grew Italian plum once (Early Italian). It was productive. As I recall it started producing at year 3. I had a President plum right next to it.

I know the arguments for and against spraying, so I won't beat on that drum. But if any of your spraying is at a bloom time in your locale, or when pollinators are active, they may be staying away or worse. If that is not the case, I would recommend planting flowering herbs, veggies or ornamentals that your local pollinators enjoy. If you keep them around and happy they will do all the work for you. For this reason I have potato bushes (for the big black bumbles), allow cilantro, arugula and nasturtiums to freely/wildly reseed (for the hover and honey bees). Oh, and the awesome blooms, fragrance and greens for salads & salsas are off the hook too.