Gardening When It Counts: Growing Food in Hard Times (Mother Earth News Wiser Living Series Book 5)

by Steve Solomon

Soil temperature and oxygen Here’s something you probably don’t already know about plants.The business of construction, of growth, is mainly done at night. Plants store up energy by converting sunshine, water, and air into sugar during the daytime. They burn that sugar as energy to grow with during the night. Assuming the plant lacks for nothing in the way of nutrition, moisture, etc., then the speed with which a plant grows is determined by temperature. For every 10°F (5°C) increase in temperature, the speed of growth doubles, meaning the size increases from 1 to 2, then to 4, and then 8, 16, 32, etc.When the nighttime temperature is much below 50°F (10°C), all biological chemical reactions, including growing, go on slowly; nothing much seems to happen. Even fruit won’t ripen much when the nights are chilly because ripening is just another form of growing. Let’s say that during a chilly evening when the temperature has dropped to 50°F at sundown, the plant will grow one size larger overnight. If the nighttime low is 60°F (15°C), the plant can grow two sizes larger. If the night is a warmer one, when the low is 70°F (21°C), the plant enlarges by four sizes overnight. On a steamy evening when people can hardly sleep and it is 80°F (26°C) at sunup, all other things being equal, the plants in the garden may have grown eight sizes overnight. That’s why on a hot midsummer’s night you can hear the corn growing.