WSU Tree Fruit Research & Extension Center

Organic & Integrated Tree Fruit Production

Friday, February 22, 2019

Cover Crops in Orchards and Vineyards

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Cover crops can perform many functions in perennial crops such as orchards and vineyards. These include erosion control, improved soil structure, nitrogen fixation, and habitat for beneficial insects. At the same time, species need to be selected carefully to avoid unintended problems with insect pests, rodents, or hosting pathogens or nematodes.


Cover Crop Workshop for Orchards and Vineyards

May 19, 2011 -- Quincy, WA Sponsored by USDA NRCS Plant Materials Center and WSU Center for Sustaining Agriculture and Natural Resources.

This event featured a series of presentations on the opportunities for cover crops in perennial fruits along with a visit to several orchard blocks planted with legume cover crops for internal nitrogen and biomass production.

Cover crops for orchards. David Granatstein, WSU Wenatchee. General principles for selecting cover crops for orchards, examples from published research, current research on using perennial legumes to supply nitrogen and biomass with mow and blow.

Cover crops for grape production. Joan Davenport, WSU Prosser. Results from screening species for alley vegetative cover without irrigation, and testing annual legumes in Concord grape vineyards for nitrogen supply.

Cover crops: inviting natural enemies into your orchards. Betsy Beers, WSU Wenatchee. Using selected flowering plants as cover crops to enhance biological control; previous research findings, testing alyssum for woolly apple aphid control in Washington State.

Enhancing biocontrol with perimeter plantings. Tom Unruh, USDA-ARS, Wapato, WA. Principes of habitat modification for encouraging biocontrol with plantings in and around orchards.  Experience with leafroller biocontrol and roses; alfalfa and pear psylla.

Native pollinator ecology and management.  Gene Miliczky, USDA-ARS, Wapato, WA.  Basic facts on native bees, classification, characteristics, and habitat needs.

Cover crop resources from the Plant Materials Center.  Pamela Pavek, USDA-NRCS Plant Materials Center, Pullman, WA. History of cover crop work, examples of useful resources, possible collaboration.


WSU Publications

Davenport, J. R., K. E. Bair, and R. G. Stevens. 2011. The Relationship Between Soil Temperature and N Release in Organic and Conventionally Managed Vineyards. Commun. Soil Sci. Plant Anal: In Press.

Mullinx, K. and Granatstein, D. 2011. Potential nitrogen contributions from legumes in Pacific Northwest apple orchards. Intl. J. Fruit Sci. 11:74-87.

TerAvest, D., J.L. Smith, L. Carpenter-Boggs, L.Hoagland, D. Granatstein, and J.P. Reganold. 2010. Influence of orchard floor management and compost application timing on N partitioning in organically managed apple trees. HortScience. 45:637-642.

Horton, D.A., T. Unruh, V. Jones. 2010. Quantifying biological control of pear psylla in a cover crop system. Final project report.

Granatstein, D. and E. Sanchez. 2009. Research knowledge and needs for orchard floor management in organic tree fruit systems. Intl. J. Fruit Science 9:257-281.

Wiman, M.R., E.M. Kirby, D.M. Granatstein, and T.P. Sullivan. 2009. Cover crops influence meadow vole presence in organic orchards. HortTech 19:558-562.

Hoagland, L., Carpenter-Boggs, L., Granatstein, D., Mazzola, M., Smith, J., Peryea, F., and Reganold, J. P. 2008. Orchard floor management effects on nitrogen fertility and soil biological activity in a newly established organic apple orchard. Biol.  Fert. Soils 45:11-18.

Bair, K. E., J. R. Davenport, and R. G. Stevens. 2008. Release of Available Nitrogen Following Incorporation of a Legume Cover Crop in Concord Grape. HortScience43: 875 – 880.

Olmstead, M.A. 2006. Cover crops as a floor management strategy for Pacific Northwest vineyards. On-line extension bulletin EB 2010.

Olmstead,M.A., R.L. Wample, S.L. Greene, and J.M. Tarara. 2001. Evaluation of Potential Cover Crops for Inland Pacific Northwest Vineyards Am. J. Enol. Vit. 54:292-303.

Also see Orchard Floor Management page for various reports that include studies of cover crops in orchards.

WSU Presentations

Assessing effects of an alfalfa cover crop on biological control and tree nutrition in organic pear orchards.

See above Cover Crop workshop.


UC SARE Cover Crop Resource Page.  Contains a range of useful information on cover crops, including orchards and vineyards. 

Cover cropping in vineyards: a grower's handbook. Ingels. C.A. et al. (eds). Univ. California DANR Publ. 3338. 162 pp.  A comprehensive reference on using cover crops in vineyards under California conditions.

Cover cropping systems for organically farmed vineyards. 2004. Glenn McGourty, UC Cooperative Extension.  Advice on selecting and using cover crops in organic winegrape vineyards.

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