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