How to Grow Vegetables in Unheated Greenhouses


Grow a variety of vegetables all year in an unheated greenhouse. Warm-weather veggies, such as tomatoes and peppers, require a heated greenhouse during the winter. But an unheated greenhouse can add six extra weeks to the beginning and end of your growing season. And you can grow cool-season crops all year with no additional heat.

Step 1

Fill 3- or 5-gallon pots with premium potting soil formulated for vegetables.

Step 2

Plant cool-weather crop seeds, such as broccoli, cabbage, carrots, lettuces and radishes. Follow specific planting instructions on seed packets. Plant most seeds 1 inch deep. Make a small indentation with your finger in the middle of the pot's soil. Place the seed in the soil and pack a light layer of soil back over the seed.

Step 3

Space seeds based on package instructions. Spacing needs vary widely among vegetables. Plant several seeds in one pot. For example, a 3-gallon pot can accommodate up to 20 carrot seeds, following spacing guidelines.

Step 4

Water daily, unless soil appears moist. Use the finger test to determine moisture. Stick the tip of your finger in the soil. If you feel moisture, skip watering. If dry, add water.

Things You'll Need

  • Premium potting soil
  • 3- or 5-gallon pots


  • The News Tribune: You Can Grow Vegetables All Year in Unheated Plastic Greenhouse
  • University of Kentucky Cooperative Extension: Greenhouse-Grown Lettuce and Greens
  • The Christian Science Monitor: Grow Plants Year-Round With a Greenhouse
Keywords: vegetables unheated greenhouse, growing unheated greenhouse, growing vegetables greenhouse

About this Author

Sommer Sharon has a bachelor's degree in IT/Web management from the University of Phoenix and owns a Web consulting business. With more than 12 years of experience in the publishing industry, her work has included "Better Homes and Gardens," "Ladies' Home Journal," "MORE," "Country Home," "Midwest Living," and "American Baby." Sharon now contributes her editorial background by writing for several Internet publications.