Cherry trees, grow best when the soil pH is between 6.0 and 6.5. If your soil tests below this range, add lime to raise the pH up to the said range. Tart cherries are self-pollinated, each plant can set fruit with just its own pollen, but sweet cherries, are not self-pollinated; they require cross-pollination from another cultivar for fruit to set. When sweet cherries are grown in humid climates they must be protected against rain-induced fruit cracking.