Best cultural practices for microgreens: A quantitative and seasonal analysis

Project Overview

FNE14-800
Project Type: Farmer
Funds awarded in 2014: $7,710.00
Projected End Date: 12/31/2015
Region: Northeast
State: New York
Project Leader:
Allan Gandelman
Main Street Farms, LLC

Annual Reports

Commodities

  • Vegetables: greens (leafy)

Practices

  • Education and Training: networking, on-farm/ranch research, workshop
  • Energy: energy conservation/efficiency, energy use
  • Farm Business Management: budgets/cost and returns, agricultural finance
  • Production Systems: agroecosystems, organic agriculture
  • Sustainable Communities: urban agriculture

    Proposal summary:

    Microgreens are small sprouted plants, often brassicas, which are harvested at the cotyledon stage or with 1-2 true leaves. Usually they are used as a garnish or high-value salad component. Small diversified farmers may benefit from growing microgreens because they can be grown year-round in a greenhouse, they are a quick turn crop, and have a high market value. Microgreens production provides a high value crop to small farmers, even when space is limited. Microgreens can be grown in a diversity of greenhouse conditions,  on benches or shelves, as long as proper air circulation and temperature are maintained.  

    A number of local farmers growing microgreens have experienced problems in production such as poor germination, mold growth, yellowing, and low yields. We believe that by taking careful records to determine appropriate growing conditions in various seasons for multiple species of microgreens, we could address the problems growers have been facing. By establishing standard cultural practices and making rigorous production data available, more people could successfully grow microgreens in their greenhouses all year. Consistent and successful production of microgreens will help farmers better market their product.

    In July 2013 we used social media to promote our Kickstarter campaign to raise money to start our new farm site in Cortland, and found it quite successful. During that time we gained hundreds of new followers (now totaling 768) on Main Street Farm’s Facebook page, greatly increasing access to fellow farmers, our peers, customers, and anyone interested in sustainable agriculture and urban farming.

    Upon completion of analysis and reporting of this experiment, we will leverage our social network to share the results. We will create a Facebook page dedicated to microgreens growing. We will also raise interest in microgreens by sharing the information gained on our website, and we will hold a workshop focused on microgreens growing for diversified vegetable farmers. Neil Mattson, an Associate Professor and Outreach Specials at Cornell University and our technical advisor, will help us coordinate and promote our event and findings.

    At that event we will display our methods, and make our production system available for others to see. A seasonal succession planning document and all yield results will be available both at the workshop, on our Facebook page and on Main Street Farm’s website. Besides social media, we can reach out to people interested in attending through our farmers market stand, and other organizations such as Groundswell, Sustainable Cortland, Cortland County’s Local Agriculture Promotion Program, NOFA-NY, Cornell Cooperative Extension, and the Cornell Small Farms Program.

    Project objectives from proposal:

    Our objective is to determine the minimum input requirements for high yielding microgreens growth in varying seasonal conditions. This information will be used to develop a seasonal succession planting guide with cultural requirements and crop scheduling information for several varieties of microgreens. In addition, this data can be analyzed with regard to economic considerations (capital, materials, utilities, markets) in order for farmers to assess the feasibility of a microgreens enterprise on their farm.  In order to explore this topic, our proposed experiment is designed to answer these two questions:

    • Which microgreens varieties are seasonally optimal for greenhouse conditions in the Northeast?

    • How much additional heat is required for optimal microgreens growth?

    Experience and preliminary research has shown that brassica seeds germinate more consistently and evenly at temperatures between 75-80F than they do at cooler temperatures. Additionally, when greenhouse temperatures are cool, microgreens growth can be accelerated by elevating the soil temperature with heating pads or with under-table radiant heat systems. Brassica seedlings can sustain growth, albeit slower, at fairly cool temperatures. 

    These facts lead us to designing an experiment where we test the efficacy of germinating microgreens at elevated temperatures, and growing them on heating pads throughout the growing season across a wide variety of greenhouse conditions. There will be three main treatment blocks (germinating/growing environments):

    1. Germinated and grown on heating pads at 80F

    2. Germinated at 80F, grown at ambient greenhouse temperatures

    3. Germinated and grown at ambient greenhouse temperatures

    In all treatment blocks the same procedure will be used for sowing the seeds: 1020 20 row seedling flats will be filled with a standard soil mix, premoistened, and then a premeasured quantity of seed will be evenly sewn across the surface of the flat. Flats will be covered with a light blocking material for the first two days of growth to aid in germination, and then the cover will be removed for the rest of the growth period.

    For the purpose of these treatments, “ambient greenhouse temperature” means that the temperature of the trays will fluctuate based on the air temperature of the greenhouse. A thermostat connected to a soil temperature probe controls the heating pads. The greenhouse that will house the experiment is partially heated, but the air inside can drop below 50F during the winter, especially at night. The soil temperature of the heating pad treatments will be maintained at a minimum of 80F, however the soil temperature of the unheated treatments will fluctuate based on greenhouse conditions, and during the colder months of the year will drop significantly below 80F. This natural variation will allow us to assess the performance of different varieties and the effectiveness of the different heating pad treatments across a wide range of growing conditions.

    Within these treatment blocks we will have 1 tray each of 8 varieties of microgreens, for a total of 24 trays per experimental cycle. Varieties will be primarily brassica microgreens, however some varieties of amaranths may also be included. Varieties will be selected based on seed cost/availability and consultation with current microgreens growers regarding anecdotal knowledge of varieties and their seasonal growth patterns.

    The experiment will be repeated each weeks for a total of 52 experimental cycles throughout the year. Data will be collected on the time it takes for the microgreens to reach harvest maturity (first set of true leaves) and the weight of harvestable microgreens produced by each tray. In addition, environmental data (air/soil temperature, light, humidity) will be recorded by a data logger and correlated with the harvest data.

    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.