Hi, I did a google search and stumbled onto this topic.
Flowering cherry trees can produce tiny little druplet fruits, but they are more fit for the birds than for people to eat. However, with the ornamental varieties of cherry blossom that are commonly planted, there are multiple good reasons why most people will rarely or never see the fruit (but I will get back to this subject later).
Are sweet cherries in the same species as flowering cherries? I have actually done some research into this, and it turns out the answer is very complicated, it’s not an easy yes or no question, for a variety of reasons. As it turns out, it IS possible to crossbreed sweet cherries with flowering cherries, and importantly the second generation offspring will be fertile (that’s not the case when sweet cherries are crossed with sour cherries). The reason generally has to do with chromosome count. Sweet cherries have 16 chromosomes. Wild Japanese flowering cherry trees also have 16 chromosomes. However, there are many ornamental cultivars which resulted from hybridization, which have 24 chromosomes. Black cherries and sour cherries, on the other hand, have 32 chromosomes. If you crossbreed sweet cherries with sour cherries, the resulting hybrid tree will have 24 chromosomes, and will still be able to produce fruit, but the seeds will be sterile (like breeding a horse and donkey together resulting in a mule, there will be no third generation).
Back to flowering cherry trees, the pink variety ‘kanzan’ resulted from hybridization many hundreds of years ago and is sterile, it will not produce any fruit. A bit of botany for you: One of the obvious indicators that this variety resulted from hybridization is the fact that the blossoms are double-flowered (2 rows of petals). This is common in other species as well (such as the yellow cotton tree), double-flowered blossoms often mean the plant is sterile and cannot produce seeds. Particular cultivars of cherry are propagated by cuttings, so the fact that they cannot produce seed does not matter.
By far the most common ornamental cherry variety is Yoshino. I was watching a documentary and there was an elderly Japanese expert who lamented that Yoshino is not really a natural variety.
Wild cherry blossom trees in Japan do produce tiny drupelet fruits. They are not very edible (the birds like eating them though).
The Yoshino cultivar is a terrible pollinator, it does not even attract bees. Those little fruits cannot form if there is no pollination.
For anyone who may be interested, I came across a published reference to Prunus campanulata being crossbred with sweet cherries. Here is the excerpt:
“Since there is no low-chill germplasm avaialable for sweet cherry, the only other alternative is to go to another species of cherry for this trait. Several species have been used in crosses with sweet cherry with occasional success with Prunus pleiocerasus and Prunus campanulata. In 1957, W.E. Lammerts made a cross between P. pleiocerasus and P. avium ‘Black Tartarian’. This hybrid is very low-chilling (<200 CU ) but not self fruitful. The hybrid was repeatedly crossed with sweet cherry and P. campanulata. In the mid 1970s, the Florida program developed several seedlings by using mixed pollen (P. campanulata and ‘Stella’). All the hybrids had pink blooms and thus were probably hybrids with P. campanulata. Several of these seedlings were fruitful. Although the size is still small, this germplasm is useful for the development of low-chill sweet cherries.”
Temperate Fruit Crops in Warm Climates, edited by Amnon Erez, p216
Prunus campanulata is the Formosan cherry, called kanhizakura in Japanese. Several hybrids of kanhizakura with other Japanese flowering cherries exist: kanzakura, okame, and youkouzakura being the three most prominent. The Formasan cherry is remarkable for being the only flowering cherry not originally native to Japan, and its ability to thrive in the Southernmost part of Japan where there is very little chill.
There are nine different varieties of cherry that grow in the wild in Japan, from which all other cultivated flowering cherry varieties originate:
Yamazakura (Prunus jamasakura)
Oyamazakura (Prunus sargentii)
Kasumisakura (Prunus verecunda)
Oshimazakura (Prunus speciosa)
Edohigan (Prunus Ascendens spachiana)
Mamesakura (Prunus incise)
Choujizakura (Prunus apetala)
Minezakura (Prunus nipponica)
Miyamazakura (Prunus maximowiczii)