While most sour cherry varieties are self-pollinating, self-pollinating in sweet cherries is the exception rather than the rule. A sweet cherry tree needs a nearby pollinator variety that flowers at the same time for good yield.
General information about the fertilization process
When the ovules in the flower have been fertilized, the flower becomes a fruit. To do this, the pollen from a male flower must reach the stigma of a female flower. In cherry trees, pollen is transmitted - as in other fruit trees - by insects, especially bees.
Pollination of the mature stigma does not always lead to fertilization. In the case of self-pollinated varieties, however, pollination of the stigma with pollen from the same flower or flower from the same tree already leads to fertilization. Provided the male and female fertilization organs are mature at the same time.
ensuring fertilization
Even with self-pollinated varieties, cross-pollination has a beneficial effect on fruit set and yield in most cases. In any case, the ability to self-pollinate does not exclude the possibility of cross-pollination. The sweet cherries Van or Erika are among the self-pollinating varieties, but with a suitable pollinator tree they consistently produce higher yields.
The sweet cherry variety Lapins, which originates from Canada, is self-pollinating and is also suitable as a pollinating variety for other cherries. Another well-known self-pollinating sweet cherry variety is Sunburst. Most sour cherries, such as B. morello, sapphire, morello fire and many others are self-pollinating. One of the tastiest sour cherry varieties - the Köröser Weichsel - still needs a suitable pollinator, which can also be a sweet cherry variety.
In order to be able to make the right combination of varieties, if necessary, the suitable pollinator varieties and the flowering time of the variety are given in the descriptions of the dealers. The flowering times should be observed as far as possible, to the extent that varieties that do not flower very early and very late are planted together.
tips and tricks
If you have enough space for several cherry trees, you can order three different cherry trees in a package online. The package contains the cherry tree varieties suitable for cross-pollination.