Getting fruit from all those flowers on a cherry tree is one of the challenges of growing cherries. Some cherry trees can’t pollinate themselves, so you may need two different varieties in the area to get fruit. Because you can’t always rely on a neighbor’s cherry tree for cross-pollination, if you want sweet cherries it’s easiest to select self-pollinating varieties. ‘Lapins’ and ‘Tehranivee’ are self-fertile sweet cherries; ‘Rainier’ needs another variety that blooms at the same time in order to set good fruit. Tart cherries are almost all self-fertile, so don’t worry about choosing only one kind or looking for the nearest possible pollinizer. Whatever type you desire, before you make a purchase be sure you check the variety you want to grow to see if it needs another tree to pollinate — and which varieties are good pollinizer candidates.
Source: Better Homes & Gardens