Winter Sprouting Broccoli as an Alternative Tunnel Crop in New England

Project Overview

Project Type: Partnership
Funds awarded in 2009: $9,981.00
Projected End Date: 12/31/2011
Region: Northeast
State: New Hampshire
Project Leader:
Dr. Rebecca Sideman
UNH Cooperative Extension

Annual Reports


  • Vegetables: broccoli


  • Crop Production: crop rotation
  • Production Systems: general crop production

    Proposal abstract:

    Vegetable farming in New England is characterized by a cooler climate and short growing season relative to other regions in the United States. As a result, many New England farmers use season extension methods including high tunnels (unheated moveable greenhouse structures) to increase yield and income from their crops. High tunnels are most commonly used for summer tomato production, and tunnels are often fallow during winter months. Due to the high value of tomatoes as compared with alternative summer crops, crop rotation in tunnels is uncommon. We plan to assess feasibility of commercial production of a new crop, Winter Sprouting Broccoli. This crop has the potential to enhance sustainability of New England vegetable operations by: - Meeting the high demand for early spring fresh vegetables for local markets - Providing an early season source of income - Using existing high tunnels when they would otherwise be fallow - Expanding low-input crop rotation options for high tunnel tomato producers In pilot studies at the University of New Hampshire, winter-sprouting broccoli (Brassica oleracea var. Italica) has shown potential as a crop that can be grown over winter in high tunnels without supplemental heat. This crop is little known in North America, but is widely grown by niche vegetable producers and home gardeners in Britain. It is biennial and winter-hardy, producing a harvestable crop in March-May after August-September planting. The harvested product differs from typical broccoli grown in the U.S. in that it produces many long lateral shoots with purple, green or white florets, and is very mild flavored. Based on our trials, we believe that the crop has tremendous niche marketing potential; acceptance and feedback from consumers and chefs has been unanimously favorable. Winter-sprouting broccoli will likely be most suited for diversified farms, particularly those farms that employ high tunnels for crop production. To identify and solve the barriers to producing this crop, potential growers that are typical of our region need to be involved. Together with a team of interested farmers, we aim to determine the best growing practices for commercial production of this crop in New England. Features of winter sprouting broccoli are: - No supplemental heat is required; many farmers already have necessary tunnel infrastructure in place - Can attract business in early spring when demand for vegetables is high and supply is low - Can be marketed as a niche crop to restaurants, cafés, coops and other markets - Is suitable to organic, conventional, and IPM growing practices - May be a suitable brassica-family rotation crop for high tunnel tomatoes with potential for reducing soilborne pathogens

    Project objectives from proposal:

    Winter sprouting broccoli, specifically referred to as either “purple-sprouting” and “white-sprouting”, are known in Europe but relatively unknown in the United States. This is reflected in their absence from most commercial seed catalogs, and the complete lack of peer-reviewed literature on development or production of this crop in the U.S.

    Researchers at the Institute for Horticultural Research in Warwick, England developed modern varieties of sprouting broccoli suitable for commercial production, and then transferred these varieties to private companies for further development (Crisp and Gray, 1985 and Crisp, et. al., 1985). Gray (1989) describes purple-sprouting broccoli as an “unworked” crop compared to other broccolis and cauliflowers.

    In 2006, the crop was first grown at UNH to determine if it would survive NH winters if protected in tunnels. Our preliminary results showed that all tested varieties of purple- and white-sprouting broccoli will grow successfully in unheated high tunnels and that the application of a poly-spun row cover increases yields. The use of black plastic bed mulch had no significant difference on yield. Studies in 2006 and 2007 were conducted using cultivars available from seed sources that primarily supply British growers (Elsoms, Bejo, Thompson & Morgan). We have been cooperating with U.S. seed suppliers (Johnny’s Selected Seeds, High Mowing Seeds) to ensure availability of seed for varieties that perform well in New England. As a result, High Mowing Seeds now offers one variety of winter sprouting broccoli. We will continue to work closely with seed suppliers and encourage them to offer seeds of the best adapted varieties for the region.

    An expanded replicated trial was planted in fall 2008 at UNH using eleven cultivars. The objectives of the current study are to determine:

    - Which varieties are best adapted to NH, with respect to total yields, maturity dates, disease resistance, and overall performance.
    - The effects of using additional rowcover within a tunnel
    - The effects of using three different planting dates (mid-Aug, early Sept, mid-Sept)

    Seeds and transplants have been distributed to six growers (including some of our grower-cooperators) as a pilot test evaluation of successful growing practices. Growers will provide feedback after the current winter on cultural practices, questions, and economic profitability, and how to incorporate this crop into successful farming operations of varying sizes. Specifically, growers will help us identify additional factors that may limit adoption of this crop so we can cooperatively address these questions in next year’s on-farm and University trials.

    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.