When you grow your own vegetables in a greenhouse, your gardening is not as subject to shifting seasons and unpredictable weather conditions as when you grow outdoors, even in the coldest, snowiest climates. Since you can manage the temperature and moisture levels in a greenhouse, you can preserve an almost summer-like growing environment, and have the benefit of a continually productive garden throughout the year. However, cultivating vegetables in a greenhouse calls for some changes to your normal planting, watering, and fertilizing methods. The best vegetables to grow in a greenhouse are those that do well indoors, such as tomatoes, bell peppers, spinach, peas, and cucumbers.
Tomatoes
Tomatoes thrive in a greenhouse but require a little bit more care than herbs do in the same environment. For example, in the greenhouse setting you’ll need to take the following special steps to make sure your tomatoes grow well and produce a lot of fruit: (1) maintain a consistent temperature of 700 – 600 F, no lower; (2) provide the plants with plenty of sun and ventilation; (3) stake the plants; and (4) add organic fertilizer or aged compost to the soil. The top tomato varieties to cultivate in a greenhouse include Cappricia, Gardener’s Delight, Sungold, and Sweet Million.
Bell Peppers
Temperature is one of the most critical factors in the proper cultivation of greenhouse bell peppers, and it also helps in determining planting times. It’s essential to provide bell peppers with the most favorable greenhouse temperatures possible. Bell pepper production demands steady daytime temperatures between 770 and 82°F and night temperatures between 610 and 64°F. Also, greenhouse bell peppers flourish at an ideal relative humidity between 65% and 85%. Thus, it’s important to keep an eye on the temperature and moisture levels for your greenhouse peppers by using a good-quality temperature and humidity monitor.
Spinach
Spinach is widely reported to be a superfood that provides the body with many important nutrients. In addition, spinach doesn’t require consistently high temperatures to thrive and does well in the greenhouse environment. Using the following tips, you can easily grow spinach in a greenhouse: (1) till the soil about a week before planting and add well-aged manure or compost; (2) sow the seeds in holes about ¾” deep and plant about 12 seeds per foot; (3) keep the soil temperature between 70°F and 75°F; (4) monitor the ambient temperature to avoid drastic variations; (5) thin the seeds approximately three weeks after they sprout; and (6) space your spinach plants about three inches apart.
Peas
Cultivating peas in a greenhouse provides you with fresh peas all through the year, and peas do well in an unheated greenhouse, as they are much more cold-tolerant than many other types of vegetables. In fact, warm weather often negatively impacts pea pod production. Actions to consider when growing greenhouse peas include keeping the greenhouse temperature at a minimum of 400F, and using lights inside the greenhouse from November through March to guarantee that your pea vines don’t grow too tall and slender.
Cucumbers
Growing cucumbers in a greenhouse allows for the extension of the vegetable’s growing season until the end of November. Even with only a limited amount of temperature control, greenhouse growing is beneficial for cucumber plants. And with suitable care, the plants can yield up to 20 pounds of cucumbers per bush. However, it’s important to cool the greenhouse with fans during the hottest days. The ideal temperature range for growing cucumbers in a greenhouse is 750 to 800F in the daytime and not less than 650F at night. Also, if the greenhouse temperature exceeds 950F, fruit production will stop.
