What to Grow: Season by Season

Growing plants in a greenhouse extends your growing season and allows you to cultivate a variety of crops throughout the year. However, different plants thrive in different seasons even within the controlled environment of a greenhouse. Here's a seasonal guide to help you determine which plants are best to grow during each season in a greenhouse.

Spring

Ideal Conditions:

  • Gradually increasing temperatures
  • Lengthening daylight hours
  • Moderate humidity

Best Plants to Grow:

  • Leafy Greens: Lettuce, spinach, kale, and arugula thrive in the cooler temperatures of early spring.
  • Herbs: Basil, parsley, cilantro, and dill can be started in spring.
  • Root Vegetables: Carrots, radishes, and beets do well in the cooler temperatures and can be sown early in the season.
  • Brassicas: Broccoli, cauliflower, and cabbage can be started in early spring for late spring to early summer harvest.

Summer

Ideal Conditions:

  • Warm to hot temperatures
  • Long daylight hours
  • Higher humidity

Best Plants to Grow:

  • Tomatoes: Varieties such as cherry, beefsteak, and heirloom tomatoes flourish in the warm, sunny conditions of summer.
  • Peppers: Bell peppers, chili peppers, and sweet peppers grow well in the heat.
  • Cucumbers: They thrive in the warm, humid environment of a summer greenhouse.
  • Squash and Zucchini: These plants grow rapidly and produce abundant yields in summer.
  • Eggplant: Requires warm temperatures and can be very productive in a greenhouse.

Fall

Ideal Conditions:

  • Cooling temperatures
  • Shortening daylight hours
  • Moderate to high humidity

Best Plants to Grow:

  • Leafy Greens: Spinach, Swiss chard, and lettuces can be planted again in the fall for a second harvest.
  • Brassicas: Kale, broccoli, and Brussels sprouts thrive in the cooler fall temperatures.
  • Root Vegetables: Carrots, radishes, turnips, and beets are suitable for fall planting.
  • Herbs: Parsley, thyme, and sage can be grown in the cooler fall temperatures.

Winter

Ideal Conditions:

  • Cooler temperatures (can be regulated with heaters)
  • Short daylight hours (supplement with grow lights if necessary)
  • Low to moderate humidity

Best Plants to Grow:

  • Cold-Tolerant Leafy Greens: Kale, spinach, and Swiss chard can tolerate cooler temperatures and lower light levels.
  • Brassicas: Broccoli, cauliflower, and cabbage can continue to be grown if temperatures are kept above freezing.
  • Root Vegetables: Beets, carrots, and radishes can be grown if temperatures are maintained.
  • Hardy Herbs: Chives, mint, and parsley can survive and grow slowly in the winter months.
  • Microgreens: These can be grown year-round and are perfect for winter due to their short growing cycle and minimal space requirements.

General Tips for Year-Round Greenhouse Growing:

  1. Climate Control: Use heaters, fans, and vents to maintain optimal temperature and humidity levels.
  2. Lighting: Supplement natural light with grow lights, especially during the shorter days of fall and winter.
  3. Watering: Adjust watering schedules based on the season and plant needs. Winter typically requires less frequent watering.
  4. Pest and Disease Management: Regularly inspect plants and maintain cleanliness to prevent pest and disease outbreaks.
  5. Soil Quality: Use high-quality, well-draining soil and amend it with compost or organic fertilizers as needed.
  6. Rotation and Succession Planting: Rotate crops to prevent soil depletion and plant diseases, and use succession planting to maximize yields.

By understanding the seasonal needs of different plants and utilizing the controlled environment of a greenhouse, you can enjoy a diverse and productive year-round garden.