Orchard Floor Management

Orchard floor management covers a number of aspects including weed control, soil health, ground cover selection and management, management of prunings, mulching, water management, rodent control, and soil amendments and nutrient additions. Often an action in one of these areas affects a number of others. For example, mulching might be used to control weeds, but can also conserve water, improve soil condition and tree performance, and enhance biocontrol of codling moth larvae with entomopathogenic nematodes.  Growers are combining recent research findings with novel management and tools to get results from a part of the orchard ecosystem that has been considered less impactful than the above ground tree.




Cover Crops

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. See the workshop presentations below:

  • 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. Principles of habitat modification for encouraging biocontrol with plantings in and around orchards.  Experience with leafroller biocontrol and roses; alfalfa and pear psylla.


Web pages

  • Cover cropping, CSANR (Center for Sustaining Agriculture & Natural Resources) webpage

WSU Publications

  • Granatstein, D., E. Kirby, and  J. Davenport. 2013. Direct-seeding legumes into orchard alleys for nitrogen production. Acta Hort. 1001: 329-334.
  • 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.
  • TerAvest, D., J.L. Smith, L. Carpenter-Boggs, D. Granatstein, L. Hoagland, and J.P. Reganold. 2011. Soil carbon pools, N supply, and tree performance under several ground cover management systems and compost rates in a young apple orchard. HortScience 46:1687-1694.
  • 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., M. Wiman, E. Kirby, and K. Mullinix. 2010. Sustainability trade-offs in organic orchard floor management. Acta Hort. 873:115-122.
  • 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.

More Resources

Mulching & Tillage




Several field trials were conducted evaluating various orchard floor strategies, including tillage, living mulch, and wood chip mulch.  Unpublished reports from these projects are presented below that contain more detailed information than the final publications.

Other Reports

Weed Management


  • Weed Control in Orchards, David Granatstein, Jan. 2015 video presentation at the Lake Chelan Hort. Day. An overview of the various methods, both chemical and non-chemical for controlling weeds in orchards.

Manuscripts/ reports

Web pages

  • Weed Management, CSANR (Center for Sustaining Agriculture & Natural Resources) webpage

2011 UC Extension Organic Tree Fruit Workshop Presentations, Sacramento, CA