Complete Zone 6 Greenhouse Gardening Guide
USDA Zone 6 offers incredible opportunities for greenhouse growers, allowing gardeners to dramatically extend their growing seasons and protect delicate crops from harsh, sub-zero winter conditions. However, greenhouses help Zone 6 gardeners extend growing seasons dramatically.
Zone 6 covers large portions of Pennsylvania, Missouri, Kentucky, Kansas, Colorado, Illinois, Indiana, and Ohio.
Zone 6 Climate Overview
Average Winter Temperatures
Zone 6 winter lows usually range from -10°F to 0°F.
Growing Season
Zone 6 has:
- Moderate growing seasons
- Cold winters
- Strong spring and summer growing conditions
Zone 6 Greenhouse Growing Calendar
January–February
- Maintain steady greenhouse heating
- Start hardy onions, leeks, and early peppers under grow lights
March–April
- Begin seeding tomatoes and herbs
- Start transplanting cool-season crops into greenhouse beds
May–June
- Main summer transplanting
- Increase watering as temperatures rise and open vents fully
July–August
- Start fall crops inside of the greenhouse
- Watch greenhouse temperatures carefully to prevent overheating
September–October
- Extend summer harvest season
- Start planting cool-season salad greens
November–December
- Protect plants from freezing conditions
- Focus on winter greenhouse maintenance
Heating a Greenhouse in Zone 6
Because winter temperatures regularly drop below zero, reliable heating is a top priority for any year-round Zone 6 grower.
Recommended Heating Options
Cold nights may require consistent supplemental heat.
Ventilation & Humidity Control
Even cold climates need greenhouse ventilation.
Important equipment includes:
Final Thoughts on Zone 6 Greenhouse Gardening
Greenhouse gardening in Zone 6 allows growers to dramatically extend their growing season while protecting plants from cold winter conditions. Proper heating, insulation, and ventilation help create a productive year-round growing environment.