Dear Good Fruit Grower:

Can sweet cherries be grown in USDA climate zone 4—successfully?

I live 20 miles north of Minneapolis in Minnesota. In the spring of 2008, I put in a test plot of sweet cherries. I planted 170 bare root trees in a Spanish Bush setting of six feet between trees and eight feet between rows. I put in six different rootstocks and 22 different varieties, all planted on a sandy loam soil in an open area.

In the spring of 2009 (after winter temperatures as low as –26°F), 138 trees froze out. In the spring of 2010 (after winter temperatures of –22°F), 22 trees froze out.

The trees left are Lapins (six trees), Sonnet (one tree), Kootenay (one tree), and Sonata (two trees), all on Gisela 6 rootstocks.

If some fruit trees can withstand -40°F and still produce fruit, what genetic factor makes this possible? Is it the climate where the plant was developed? Who in the United States works on developing fruit trees for zone 4 or even zone 3? Who else uses Prunus maackii as a rootstock for sweet cherries?

My research I do as a hobby. If anyone is interested in this project, contact me at jumbogage@aol.com.

Jim Gage
Lino Lakes, Minnesota