First time poster, lurker for years. I have an issue that is frustrating me to no end with two of my plum trees.
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?