High Value Crop Rotations for Utah High Tunnels

2009 Annual Report for SW07-035

Project Type: Research and Education
Funds awarded in 2007: $144,495.00
Projected End Date: 12/31/2010
Region: Western
State: Utah
Principal Investigator:
Brent Black
PSC Department, Utah State University
Dr. Brent Black
Utah State University

High Value Crop Rotations for Utah High Tunnels


During Year 2 of this project, additional high tunnels were constructed at the Greenville research facility, bringing the total at the facility to 12. Replicated research trials evaluated winter lettuce and spring tomato, summer and fall raspberry and blackberry, and various strawberry production systems. The two graduate students hired have fully initiated their research projects, presented some preliminary findings to local growers, are refining the production systems, evaluating economic viability and solving physiological problems associated with this project. Presentations and hands-on workshops communicated the results of the projects to over 150 individuals from throughout Utah, with many commercial operations implementing this approach.

Objectives/Performance Targets

  1. 1) To characterize the effect of high tunnels on crop productivity for a range of vegetables and small fruits grown early and late in the annual crop production cycle.
    2) To determine compatible crop rotation strategies under organic production techniques.
    3) To compare in-ground to containerized bench-top planting strategies for effectiveness in season extension and labor efficiency.
    4) To assess the economic benefits of these different crop sequences and management techniques.
    5) To distribute this information to urban and rural farmers and home gardeners of Utah and the Intermountain West at local field days, at extension educational events, and through print and electronic forms.


1) There are 12 high tunnels in use at the Greenville Research Farm in North Logan. Toward objectives 1 and 2, experiments have been conducted to evaluate: spring tomato production using low energy supplemental heating to improve early growth; winter lettuce production systems; and spring and fall strawberry and raspberry, and summer blackberry production.
a) Simple protection systems like tunnel-within-tunnel, soil warming with heating cables, and low wattage light bulbs significantly increase soil and air temperatures in the spring thus enhancing early growth of tomato. Tomato harvest began on July 7, despite an unusually cold wet spring. Tunnel production is usually more than one month earlier than outdoor grown tomatoes in Northern Utah. Early price at the Logan Farmers Market is $2/lb and product sells briskly.
b) Early fall and late spring lettuce production in raised towers is more productive than ground-based systems. When adding supplemental heating cables to the soil, growth is even greater. Higher plant populations and improved space utilization make these potentially viable systems. Crops can be cycled through the systems in 6-8 weeks depending on time of year. Lower mid-winter production levels are due to light and soil and air temperature limitations. Enterprise budgets for these rotation schemes will be developed and should be published during the end of this funding cycle.
c) Advancing summer-bearing raspberry cultivars to produce in early spring has been problematic due to protecting floricanes from winter temperature fluctuations that injure flower buds. We have worked on identifying better tunnel temperature management but continue to see excessive winter injury. In 2009 the first harvest came on July 6th, with half cup (6 oz) clam shells selling for $3. We need to further refine the system and better understand how temperature impact winter hardiness, dormancy, bud break and cane injury.
d) Two strawberry production systems are being investigated for extended season production. A fall-planted system using June-bearing varieties gives good production starting in May. Day-neutral varieties established in late winter/early spring produce through the summer and fall. With the combination of systems, strawberries were harvested from May 1 to December 15. Produce has been marketed at $3/lb.
e) We are beginning to understand the needs for tunnel management of blackberry. More effort is needed in this area in the next year. During the next funding year, work will continue to further refine each of these systems and to gather information on inputs and productivity.

2) Tunnels equipped with a combination of vertical growing systems and ground-based beds are being used to address objective 3. The vertical systems, filled with soilless potting media have been tested for fall-winter and spring planted lettuce and fall planted strawberry production systems. The decreased mid-winter productivity in lettuce appears to be related to lower root activity and less nutrient uptake brought on by greater root zone temperature fluctuation. We tested this hypothesis by inserting low wattage heating cables and measured a significant improvement in lettuce growth compared to the unheated controls. Strawberries grown in the vertical systems in the spring of 2008 did not show significant yield increases over ground-based systems, primarily due to mid-winter injury in the vertical system. With some modifications to overwintering procedures during the winter of 2008-09, we are seeing increased productivity in the vertical system.

3) Productivity data (growth, yield, quality) and crop input information are being collected from each of the systems to address objective 4. M.S. graduate student Daniel Rowley has been working on methods to improve the growth and production of strawberry and raspberry systems and collect data on inputs and productivity. He has drafted enterprise budgets for each of the cropping systems that are currently under review. M.S. graduate student Britney Hunter is responsible for the methods to improve the growth and production of winter lettuce and spring tomato production systems, to devise methods to mitigate cold temperature effects on early season growth, and collect input cost/returns data on these systems. She will be working with Mr. Rowley to develop enterprise budgets for the vegetable systems.

4) A series of field days, presentations and other events have been conducted to introduce the technology to growers, gardeners and the public (address objective 5).

a) Dr. Brent Black, Dr. Dan Drost and USU students, Ms. Britney Hunter and Mr. Daniel Rowley conducted a workshop on 4 November 2008 for 16 growers demonstrating that there are additional market opportunities for this late fall-winter season production strategies. Most growers use high tunnels for early spring markets. Few growers have exploited later season production opportunities. Growers were shown production data for fall squash and tomato (Dan Drost), winter lettuce (Britney Hunter – MS student), fall strawberries (Daniel Rowley – MS student), as well as opportunities for blackberries and raspberries (Brent Black). Cropping strategies were introduced, participants went on a walking tour of the High Tunnel Research Block and grower comments, questions, and observations were addressed.

b) During January 2009, Brent Black notified Utah Extension Field Staff of our interest in conducting High Tunnel workshops in different areas of Utah. Shawn Olsen (Davis Co, urban Salt Lake City region) worked with us to organize the meeting and identified a grower interested in having a tunnel constructed on his farm. Thirty-two commercial small fruit and vegetable growers heard ½-hr presentations on fruits and vegetables from Black, Drost, Hunter and Rowley. The grower’s then built the end walls of the USU designed High Tunnel (see attached photographs) (http://extension.usu.edu/files/publications/publication/HG_High_Tunnels_2008-01pr.pdf). After a Western SARE sponsored lunch, the participants went to David Day’s farm in West Layton where they laid out a tunnel and the participants assembled it for the grower. The next week the grower constructed a second tunnel, planted the tunnels and now is harvesting early tomatoes for his roadside stand. The workshop was published in the Utah Berry Growers Association newsletter (http://extension.usu.edu/files/publications/newsletter/ubgannewsletterApril09.pdf).

c) Ron Patterson (USU Extension Educator – Carbon Co.) organized a day-long workshop on April 4, 2009, for small farmers and market gardeners from central Utah. Ron has been working with the Price Farmers Market and helping educate growers there about the benefits of high tunnels to increase produce supplies to the market. Twenty four farmers and market gardeners heard ½ hr presentations on fruits and vegetables from Black, Patterson and Rowley, they then constructed end walls, and learned to layout and assemble a high tunnel.

d) Extension Educators Kevin Heaton (Garfield County) and Lisa Lewis (Wayne Co) organized a tunnel workshop on April 16, 2009 focused on the benefits for Utah’s high elevation (6000 ft+) counties where home garden production of warm weather crops is challenging. The meeting was organized in cooperation with Junction High School (they agreed to have the tunnel constructed on school grounds) and 27 local gardeners and growers in Garfield, Wayne, Piute, and Iron counties. Participants heard ½ hr presentations on fruits and vegetables from Black and Heaton, and they constructed and assembled a tunnel at the school where the local science teacher (Sherida Allen) will use it for community and school educational projects.

e) Graduate students Britney Hunter and Daniel Rowley, in an attempt to collect meaningful market data, have been marketing and selling early strawberries, raspberries, and tomatoes through the USU teaching greenhouse Plant Shop and at the Logan Farmers Market Consumer interest is quite high with a story appearing in the local newspaper. http://hjnews.townnews.com/articles/2009/07/01/news/news02-07-01-09.txt

Impacts and Contributions/Outcomes

The workshops, presentations, phone calls and emails related to this project have disseminated information on high tunnels and high tunnel production strategies to over 150 participants throughout the Intermountain West. While audience size does not necessarily equate with technology adoption, we are aware of several instances where commercial farms are adopting this technology.
1. Half the commercial growers who attended the March 2009 workshop already have or intend to build high tunnels on their farms to grow a variety of crops. Most growers build more than one tunnel and all are at least 100’ long. As they gain experience, they have been sharing their experiences with others interested in tunnels.
2. Local tomato growers throughout Utah report that production starts 4-6 weeks before outdoor production and returns are $2-3/lb at the farm gate.
3. There is continued interest in high tunnels for home gardens due to the economic crisis and renewed interest by the public in growing more food at home. A second home gardener/Master Gardener workshop is being organized by local extension staff for September 2009 for Weber and Davis Counties in Northern Utah.
4. Early marketing and sales show strong consumer interest. Produce sales suggest early net returns of between $2.50 and $5.00 per sq ft of tunnel space for raspberries and blackberries, $4.00 to $5.00 per square foot for strawberries and $1.75 to $3.00 per sq. ft. for tomatoes.


Ruby Ward

Associate Professor
Economics Department, Utah State University
3530 Old Main Hill
Logan, UT 84322-3530
Office Phone: 4357972323
Dan Drost

PSC Department, Utah State University
4820 Old Main Hill
Logan, UT 84322-4820
Office Phone: 4357972258