Organic Strawberry Production: Extending the Season with Low Tunnels

Project Overview

Project Type: Farmer/Rancher
Funds awarded in 2008: $10,000.00
Projected End Date: 12/31/2011
Region: Southern
State: Alabama
Principal Investigator:
Carol Garrett
Auburn University

Annual Reports


  • Fruits: berries (strawberries)


  • Education and Training: on-farm/ranch research, workshop
  • Farm Business Management: marketing management
  • Production Systems: organic agriculture


    This project was designed as a demonstration project to determine if the strawberry harvest season could be extended by simultaneously employing four different production methods and growing three different varieties designed to spread out production and harvest over a longer period of time.

    The treatments were:
    Treatment 1 Bare ground, no low tunnel
    Treatment 2 Bare ground, low tunnel
    Treatment 3 Black plastic, no low tunnel
    Treatment 4 Black plastic, low tunnel

    The 3 strawberry varieties planted were:
    1. Allstar
    2. Camarosa
    3. Chandler

    Black plastic mulch produced berries 1-2 weeks earlier than the matted row system; plants on black plastic mulch with a low tunnel produced berries about 1 week earlier than those on black plastic mulch without a low tunnel. In the matted row system the low tunnel produced a greater number of berries earlier than without the low tunnel, but the total number of berries produced was greater without the low tunnel in both the black plastic mulch system and in the matted row system. The matted row system produced more berries than the black plastic mulch system, but reguired more labor picking and weeding.

    Chandler produced the most amount of fruit, followed by Camarosa, and Allstar produced the least amount. Camarosa consistently produced a superior high quality berry; large, well shaped, very tasty, and fewer diseased berries.


    Organic farmers need to maximize profits with high-value locally produced fruits and vegetables. Strawberries are a high value crop, especially if they can be advertised as being locally grown and pesticide-free. Farmers who can get their strawberries to the market early can obtain premium prices for them. Strawberries from Florida are available early in the year, but they are not harvested ripe and are not pesticide-free. Low tunnels provide an opportunity for local organic growers to economically produce early berries. Growing strawberries in a greenhouse or high tunnel requires a large monetary investment, which is not practical for the small-scale, beginning, or limited resource farmer. Low tunnel strawberry production, however, could help farmers increase their profit margin and enhance their economic sustainability.

    Project objectives:

    1. Investigate the profit potential of early strawberry production using low tunnels.
    2. Compare the performance of 3 different strawberry varieties in the traditional matted row system and plasticulture under low tunnels and organic production methods.
    3. Design economical and functional low tunnels that would be adapted by limited resource farmers.

    Low tunnel strawberry production would be an affordable production method that would allow local farmers to harvest earlier and obtain premium prices for their product. Farmers would obtain many of the same benefits as they would with unheated greenhouse production, yet they would have less production expense. Low tunnels, unlike high tunnels and greenhouses, can be easily moved around to permit crop rotation for pest control. Low tunnels are also an economical way to protect the crop from herbivore pests, such as rabbits and deer. Locally grown foods produced with low tunnels would be a more sustainable practice than importing these items from other areas of the country. Most of the materials used for low tunnel construction can be re-used for multiple growing seasons.

    Strawberry production has shifted away from the traditional matted row system and gone toward plasticulture due to weed and disease problems and increased yield with the latter method. However, plasticulture is a more expensive and labor intensive production method and involves some sustainability issues, i.e. disposal and use of petroleum products.

    Strawberry variety trials in this area have not included organic growing methods. I would like to compare the performance of a few of the popular varieties under organic growing conditions and low tunnels. It is possible that the varieties that perform best under conventional production methods would be different from those that perform best in an organic system that depends on slow-release organic fertilizers and ecologically based pest control methods. In a sustainable organic system with a focus on local marketing, other plant characteristics besides yield and shelf life might assume high priority. Characteristics such as plant hardiness, competitiveness with weeds, and fruit taste might be more important in this system.

    In order to become accepted and adopted on a large scale, low tunnels must be user friendly. They need to be inexpensive to construct, easy to manipulate, and the materials should last for multiple years. The sides will need to be opened during warm weather and additional coverage may be needed on very cold nights.

    Spring 2008
    Beds will be prepared for planting.
    Strawberry plants will be planted in 6 of the new beds and mulched with hay.
    The other 6 beds will be planted in a summer cover crop of cowpeas.

    Summer 2008
    The strawberry plants will be kept weeded, watered, and will be side-dressed with composted manure and worm castings.

    Fall 2008
    The plants will be thinned.
    The 6 beds that were planted in cowpeas will be covered with black plastic, fertilized, and planted with the 3 varieties.

    Winter 2009
    The beds that will receive the low tunnels will be covered. The covering will be manipulated as the weather dictates.
    Fruit will be harvested as produced and records will be kept on weight and dates of harvest.
    Fruit will be sold in Auburn and Tuskegee.
    Spring 2009
    Harvest and fruit sales will continue.
    Strawberry plants in the matted rows will be fertilized.
    Summer 2009
    Beds will be kept weeded and fertilized.

    Fall 2009
    Matted row beds will be renovated.
    Plastic mulch beds will be rotated to different areas. New beds will be planted.
    The results of the study will be presented at the Annual Organic Vegetable Production Conference.
    A poster or a talk will be presented at the Deep South Fruit and Vegetable Growers Conference.

    Winter 2010
    Repeat of winter 2009, with management adaptations.

    Spring 2010
    Repeat of spring 2009
    A field day will be held on the farm.
    The final report will be submitted.
    The results will be published in the Organic Vegetable Production e-newsletter.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.