Evaluating Vegetable Varieties for Winter and the Shoulder Seasons in Zone 7: Best Practices, Marketability, and Profitability

Nearly all winter leafy green vegetables sold in the United States are grown within 100 miles of Yuma, Arizona (Seronde, M). From December through May, local vegetables are scarce in the Northeast. As a result, vegetable farmers in the region face limited income during the winter months, which can last for nearly half the year. This seasonal downturn often leads to difficulties maintaining a full workforce and keeping employees on payroll. Meanwhile, consumer demand for fresh, local vegetables is especially high during the winter when sourcing locally is particularly challenging.

An additional problem is environmental. Consumers in the Northeast rely heavily on vegetables grown thousands of miles away, contributing to a significant carbon footprint due to the high costs of cooling and transportation. Most of these vegetables, including leafy greens, are grown in Yuma, Arizona, which requires extensive energy to transport and cool them for national distribution. Shifting cultivation to the Northeast during the winter, particularly when imports are high, could reduce this environmental harm and support the local economy.

Timing the production of vegetables, especially leafy greens, for the winter and early spring months is a major challenge for farmers. Even with access to heated greenhouse space, such as propagation greenhouses commonly found on many farms, growers face unique difficulties in cultivating winter vegetables. To harvest fresh crops during the winter months, farmers must plant varieties that can tolerate both the extreme heat of late summer and the cold, dark days of winter. These crops must also be resilient enough to withstand the hot early spring days that can trigger bolting. Additionally, farmers must manage day-length requirements during the shortest days of the year. For some vegetables, this can be a complex challenge, requiring precise control of temperature, water, and fertilizer to ensure crops are ready on schedule.

Despite the potential for high payoff, timing vegetables for the winter and early spring is often a gamble for farmers in the Northeast. Unlike field-grown plants, high-tunnel vegetables require daily maintenance—remay coverings must be applied and removed, tunnels need to be opened and closed, and irrigation systems must be carefully managed, all of which come with additional costs. While many farmers lack in-ground heated high tunnels, many have unused propagation greenhouses that sit dormant from late summer to early winter, after seed starting is complete. These greenhouses could be repurposed to grow microgreens for the winter with minimal heating, instead of remaining idle.

This project aims to test which vegetable and microgreen varieties can be successfully grown and marketed by local farmers during the winter and early spring seasons. We will evaluate six different vegetable and microgreen groups for their potential as profitable winter crops for Northeast farmers: bagged greens (salad mix, baby kale, arugula, Asian greens, spinach), kale, carrots, celery, microgreens (pea leaves, pea tendrils, cilantro, broccoli shoots, radish shoots), and Asian greens (bok choy, tatsoi, napa cabbage). For each group, we will identify key horticultural best practices, such as seeding and planting dates, optimal day and night temperatures, and the need for supplemental heat.

We will trial these plants both in-ground and in greenhouses to provide options based on farmers’ existing infrastructure. By tracking input costs, labor, and sales, we will analyze the profitability of each crop. This will help determine which vegetables offer the greatest income potential for farmers. Additionally, we will assess the marketability of these crops to both retail and wholesale markets. For retail consumers, we will track farmers' market sales, gather customer feedback, and monitor pricing trends. For wholesale customers, we will distribute a survey to gauge interest in purchasing local vegetables throughout the winter months.

The Northeast is a major producer of vegetables in the United States from May through November, but production drops significantly after Thanksgiving. Most winter crops in New Jersey consist of storage vegetables harvested in the fall, rather than fresh produce. This project will provide farmers in the region with accurate information on how to successfully grow vegetables year-round, including winter and early spring, and which varieties are best suited for their farm’s infrastructure and market. Armed with this knowledge, farmers will be able to extend their sales into the highly profitable winter season, enhancing their net farm income.

This extension of the growing season will also contribute to steadier, year-round employment for farm workers who often face unemployment during the winter months. By providing consistent work opportunities, farmers will be better able to retain skilled labor year-to-year, reducing training costs and improving the quality of life for farming communities. In turn, this can foster stronger local economies, support sustainable farming practices, and create a more resilient regional food system.

Through this project, we aim to empower farmers with the tools, knowledge, and strategies needed to expand their operations and meet the growing consumer demand for local, fresh produce year-round. By increasing the availability of winter vegetables in the Northeast, we not only reduce reliance on imported produce but also promote environmental sustainability and enhance the vitality of local farming communities.