I planted two Nanking cherries in 2013. They have grown well and are now 5 ft tall and around. The past two years they had wonderful flowers but no fruit. Can you help me understand why and if there is anything I can do to promote fruit development?
Your Nanking Cherry non-fruit bearing problem may stem from one of several possibilities.
Although the Nanking Cherry is a “self-pollinator”, cherry trees are highly dependent on honeybees for pollination. If honeybees bees are either not localized, or delayed are thwarted by rainy weather , this can still be one of the culprits if no bees are available at the time the blooms are offering.
To rule this out next year you can try to observe the presence of bees when the blossoms are opening. You can also augment the pollination process through self-pollination.
I have attached a link for a video that helps show you this process.
- Monitor the cherry tree or trees for blooms. If you have a sour cherry tree or self-fruitful sweet cherry variety you can begin to pollinate the tree by hand as soon as flowers open and pollen is released, or if it is visible on a finger that you brush across the flower’s anthers.
- Touch the tip of a cotton swab or small artist’s brush to the pollen-covered anthers so that pollen grains are visible on the implement.
- Touch the pollen-covered brush or swab to a receptive stigma, which may look shiny or sticky, in the center of a flower. Pollen is usually visible on the stigma where it is adhered. Continue to transfer pollen from one tree to receptive stigmas on another, working around the tree until you have made contact with most of the open, receptive flowers. Pollen is usually visible on the stigma where it is adhered. Continue to transfer pollen from one tree to receptive stigmas on another, working around the tree until you have made contact with most of the open, receptive flowers.
- If possible, pollinate the tree or trees midday on warm days, as this is when a flower’s anthers shed pollen most readily.
- Even if ample insect pollinators seem to exist in an area, hand pollination is sometimes necessary if the insects are disrupted by wind, rain, cold temperatures or other factors.
In summary I believe that the pollination issue is the most likely scenario, hence I hope your self-pollinations …. Bear fruit!
Other possible contributing factors
Maturity – Natking Cherries may take several years to reach a maturity , before which time they may bloom and not produce fruit ( similar to your situation). However since you have stated that you have had your trees more than 4 years and their size, that is not likely to be the primary factor.
Fertilization – These cherry trees do not require a high amount of extra fertilizer, but the wrong type of fertilizer can cause the tree to forgo energy into fruiting and put it into vegetative growth. For example a high nitrogen fertilizer will promote this result.
Pruning – Correct practices are important, as excessive upright growth will delay fruit bearing and reduce the quantity
Weather patterns – Hard freezes in the winter of less than (-29 degrees F), can damage flowering buds, that thwart fruit production after flowering. In the past 2 harsh previous winters this may have occurred, but after a cold start this past winter there were few extreme cold snaps. Hence this is not the likely cause.
In summary, it sounds like the pollination issue is the most likely cause, hence I hope your self-pollination efforts …. Bear fruit!