Cross Pollination Wrong

Asked March 20, 2020, 9:45 AM EDT

Hi. My neighbor just told me that last year my 2-3 year old Royal Ann crossed with these BIG, OLD, pit cherry trees. They're kind of like an overgrown pie cherry tree with PLENTY of fruit, but not for eating! I don't know what they're called. She called them seed cherries. I didn't even know you needed more than one cherry tree. Now last year my 5 yr old Bing did ok, but the new 2-3 yr old Royal Anne was like 1/2 puny (pit??) cherries and 1/2 Bing. No Royal Anne's on the entire tree! Today I found a baby Rainier. Can the accidental cross pollination be undone by adding this new Rainier, or should I just give up before I take up my whole yard? How far away should I plant the new Rainier? The Bing and the Royal Anne are close to each other but those big old pit cherry trees are clear across the yard. I live on an acre. Also, what hardiness zone is Lebanon, Oregon? I appreciate your advice. I need it! I have never pruned any of them either. I don't know how and don't want to mess it up. Okay. Thank you.

Linn County Oregon

1 Response

Most sweet cherry varieties are self-unfruitful (self-incompatible, SI) and require cross pollination with another variety as the pollen source.

Some varieties, e.g. Bing, Lambert, Royal Ann/Napoleon, are also cross-unfruitful and cannot be depended upon to provide pollen for each other. Index, Lapins, Skeena, Sweetheart, White Gold, Sonata, Stella, Symphony, Sunburst, and Black Gold are self-fruitful (SF) and can serve as “universal” pollen sources for many self-unfruitful varieties with the same bloom time. However, Stella has been found to not work as a pollinator for Bing in some areas.

Their use as “universal” pollinators should also take bloom timing into consideration as follows. Early-bloom: SI – Somerset; SF – Lapins and Skeena. Early- to early-mid-bloom: SI – Kristin, Chelan, and Black Republican; SF – Sweetheart and WhiteGold. Mid- to late-mid-bloom: SI – Royalton, Summit, Ranier, Royal Ann / Napoleon, Bing, Burlat, Van, Regina, Lambert, Sam, and Windsor; SF – Sonata, Stella, Symphony, and Sunburst. Late-bloom: SI – Gold and Hudson; SF – BlackGold.

When it comes to fertilizer, feed the soil rather than the tree. If the tree appears happy an application of compost in early spring will be sufficient. If you think the tree needs more of a boast do a soil test first to determine what type and how much nutrient should be added. If the growth rate seemed slow the previous year an application of nitrogen may be called for. Apply it at a rate of 1/8 of a pound per inch of the diameter of the trunk. Fruit bearing sweet cherries will grow about 10 to 15 inches every year; sour cherries grow at a rate of 8 to 10 inches every year.

Pruning cherry trees is important for tree strength and fruit production. This task should be done every year during the dormant season.

Here are some publications you will find useful:

http://treefruit.wsu.edu/web-article/sweet-cherry-pollination/?print-view=true

https://extension.oregonstate.edu/crop-production/fruit-trees/sweet-cherry-compatibility-bloom-timing-chart

https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/ec819.pdf

Hope this helps!