Cherries: Organic Production
This publication focuses on organic pest and disease control and other topics relevant to organic production of both tart and sweet cherries. It introduces the Canadian bush cherry and discusses climatic considerations for cherry production. Information on marketing is included, as are further resources and sources of trees and pest-control materials.
Commercial organic cherry production presents many challenges. The cherry fruit fly, bacterial canker, phytophthora root rot, leaf spot, fruit cracking, late frosts, and brown rot of the blossom and fruit are all serious obstacles to the orchardist hoping to make a profit with cherries, particularly for the organic grower. Yet, despite these and other hurdles, organic cherry production is a profitable option for U.S. growers in much of the Northwest, and in the East, light can be seen at the end of the (high) tunnel.
Sweet and tart cherries belong to different species, and the differences between these species drive management choices. Compared to tart cherries (Prunus cerasus), sweet cherries (P. avium) are taller (30 to 40 feet unpruned on standard rootstocks), produce larger fruits, are somewhat more susceptible to diseases, require cross-pollination, are less cold hardy, and are usually hand-harvested for the fresh market.
Tart cherries are short (18 to 20 feet unpruned on standard rootstocks), are cold hardy, have fruit more resistant to cracking and brown rot (relative to sweet cherries), are self-pollinating, and most are machine harvested for the processing market.
A third and new type of cherry, the Canadian bush cherry, resulting from controlled crosses between P. cerasus and P. fruticosa (the Mongolian bush cherry), seems to be poised for successful commercial production in Canada and, probably, the United States. Breeding advances in Canada have resulted in a bush that yields large amounts of sweet-tart cherries (18 to 22 brix), is cold hardy to minus 40°F, disease resistant, and suited to mechanical harvest with blueberry harvesters.
Recent advances in developing dependable, dwarfing rootstocks for cherries benefit conventional and organic growers alike, but may greatly increase the viability of organic operations, especially in the East, because the smaller size will enable them to be grown inside high tunnels (plastic-covered hoop houses). Th is protected growing condition reduces problems associated with rainfall and fluctuating temperatures (see box “Trees in Tunnels” on page 3). Some of the dwarfing rootstocks are also more genetically resistant to bacterial canker and root rots than the standard types currently used.
Many considerations and practices are the same for both organic and conventional cherry growers. Cherries prefer a deep sandy or sandy loam soil with a slightly acid to neutral pH. A pH of 6.2 to 6.8 is often cited as ideal. Pruning and training will be approximately the same for all kinds of culture. Information on these topics is available from sources such as the Cooperative Extension Service, state cherry production councils, orcharding texts, and trade magazines. This publication focuses primarily on organic pest and disease control and other topics relevant to organic production.
- Climatic Considerations
- Trees in Tunnels
- A New Type of Cherry: The Canadian Bush Cherry
- Rootstocks and Organic Production
- Major Insect Pests
- Major Diseases