Sweet Cherry Pollination

Qpine branchuestion: I have a Bing cherry tree in my yard that is several years old. Some years the tree has bloomed and some years it hasn’t. Even years when the tree bloomed it didn’t have cherries. I’ve heard some fruit trees need another tree for pollination. Is this true in sweet cherries and what do you recommend? F.M.

Answer:  Growing sweet cherries in southern Wisconsin is challenging. Most cultivars of sweet cherry bloom in early spring so the flowers can be damaged by late frost.  However, a few home gardeners successfully grow sweet cherries in southeastern Wisconsin.  The odds for success increase if you live close enough to Lake Michigan to benefit from lake effect microclimate. Lake Michigan moderates winter cold and decreases significant spring temperature swings. Bing cherry is rated cold hardy for our zone 5, which explains why your tree has bloomed part of the time.

The majority of sweet cherries, including Bing, are self-unfruitful. To produce fruit the flower must receive pollen a different cultivar of sweet cherry. For good cross-pollination the two unlike sweet cherry trees should be planted within 100 feet of each other. To further complicate the problem, some cultivars of sweet cherries won’t cross-pollinate. Bing cherry can’t be pollinated by Lambert, Napoleon (Royal Ann), Star or Emperor Francis, and vice versa. All other cultivars or varieties of sweet cherry, which bloom at the same time, will pollinate the flowers on your Bing cherry tree. Based on recommendations from several Midwestern universities Rainier, Van, Sam, Windsor or BlackGold would be good choices as cross-pollinators for your tree. These cultivars are hardy and bloom in mid to late spring.

Van, Sam, and Windsor cherry trees produce firm, dark mahogany fruits. Rainier trees bear firm yellow cherries with a pink blush. Rainier are the best of the four types for eating fresh.

BlackGold is one of a few sweet cherry cultivars that are self-fertile. Self-fertile varieties are good pollinators of self-unfruitful cultivars in addition to being able to pollinate their own flowers. BlackGold blooms late in spring and is very tolerant of late spring frosts. The fruits of BlackGold are dark red and especially good for eating fresh. Self-fertile sweet cherries are especially useful for small yards where there isn’t room for two trees. Another self-pollinator is WhiteGold. It blooms earlier than BlackGold and bears yellow cherries with a red blush. WhiteGold cherries are recommended for cooking and processing.

 

Barb Larson is horticulture educator for Kenosha County University of Wisconsin Extension. Barb has a Master’s of Science in horticulture from the UW-Madison. If you have a plant or gardening question, email Larson at barbara.larson@kenoshacounty.org  or call her at 262-857-1945.