Winter greens thrive in tunnels - boosting income

By Blake Jackson

Farmers markets burst with vibrant greens in the heart of winter, thanks to the magic of high tunnels. These innovative structures protect crops from harsh weather, allowing growers to cultivate spinach, lettuce, and other leafy delights even when the ground outside is frozen. 

Lucrative Greens and Extended Employment: 

Beyond extending the growing season, high tunnels offer several benefits. Winter greens command premium prices, sometimes reaching $10 per pound. This translates to significant income for farmers, especially during the traditionally slower winter months. Additionally, cultivating these crops throughout the year helps maintain a steady workforce, reducing the need for seasonal layoffs. 

Planting Strategies and Maximizing Yields: 

Experts recommend early planting dates, ideally around mid-October, for optimal yields. Direct seeding or transplanting seedlings in paper pots are both viable options. High planting density efficiently utilizes the valuable tunnel space and promotes upright leaf growth, facilitating clean harvests. 

Harvesting Techniques and Overcoming Winter Challenges: 

Some farmers harvest greens leaf by leaf, while others opt for the faster clear-cutting method. Winter brings its own set of challenges. Growers protect lettuce and bok choy from extreme cold with row covers, while spinach, surprisingly, tolerates freezing temperatures. Covering spinach might be necessary during extended periods of single-digit temperatures. 

Maintaining Plant Health and Soil Management: 

Winter greens are susceptible to fungal diseases like damping off and downy mildew due to high humidity under row covers. Planting cover crops in the summer helps foster beneficial soil microbes that combat these issues. Steaming the soil is another option for sanitation, but it's time-consuming and expensive. 

Moisture Management and Ventilation: 

Winter greens thrive in well-drained soil. Farmers like Jennifer Glenister from New Morning Farm prioritize irrigating deeper soil layers (3-6 inches) and avoid overwatering the top 3 inches. Proper ventilation is crucial for managing humidity and bringing in fresh air. Automated systems can efficiently regulate temperature and air exchange within the tunnel.

Photo Credit: pexels-patrick-jennings