Ten Year Old Cherry Drops Fruit Before Maturity
I have a 24 foot, 10 year old healthy looking Black Tartarian Cherry tree. It gets cherries but they always drop off prior to maturity. There are three apple and a Lapins Cherry (small) tree in the same area (within 100 feet). Why does it not produce fruit?
There are a couple of possibilities. Black Tartarian blooms very early compared to other cherry varieties. This early bloom may mean that the blooms are damaged by frost during bloom, so that there are no, or only a small number of viable flowers on the tree.
The other possibility is the trees may be blooming at different times. The Lapins cherry tree blooms a bit later than the Black Tartarian. It is possible that the Black Tartarian is finished, or mostly finished blooming by the time the Lapins blooms. Your Lapins tree does not have the same problem, because it is self-fertile (it does not need another variety for pollination to occur). If this is the problem you would need to purchase and plant another cherry tree that blooms at the same time, such as Samba or Sommerset. You could also graft a few branches of a compatible variety that blooms at the same time onto your Black Tartarian tree.
A couple of other possibilites that are less likely is that the tree may be deficient in boron or it may be shaded out by other, larger trees. Both of these cases would cause the fruit to drop.