Sour and sweet cherries can be grown in Delaware. Sour cherries are more likely to produce a crop. Normally, trees will live 15 to 20 years before they become unproductive. Sour cherries do not require cross-pollination.
Some sweet cherries require at least two varieties to be productive.
Some of the newer varieties do not need cross-pollination, but will usually produce more fruit when they are. If space is limited, consider planting the new bush-type cherries. Montmorency is the old-standard sour cherry variety. It is still good today. Standard sweet varieties are Windsor, Napoleon, Black Tartarian, Schmidt, North Star, Hedelfingen, and Bing.