Warm Winter Good For Humans, Bad For Plants
There’s a lot going on, biologically, below the surface, much that can influence what we see on market tables for the rest of the year. And much that can go wrong if the winter is warm, as this one has been in the Northeast.
First, the deep, killing subfreezing cold of winter typically eliminated many damaging insects and pathogens.
Beyond killing the baddies, proper cold serves another important purpose: for perennial crops, shorter days and sustained low temperatures bring a cycle of dormancy, a deep, almost anesthetized sleep, during which growth is temporarily halted. Measured in “chilling hours,” this is the time when plants’ energy is held in reserve, building up for new growth, and farmers can prune and transplant without fear of sprouting. Without sufficient chilling time, a fruit tree will generate fewer, weaker buds, limiting fruit production from day one. Growers monitor chilling hours in a season with a wary eye.
[A] winter that warms up too much for too long, causing plants to “think” it’s spring, could be truly disastrous if temperatures revert and freeze again. In the Wölffer vineyards, Pisacano worries about his vines’ fragility as they come out of dormancy; if a freeze hits then, their trunks could split, causing fatal damage. As Dr. Carroll explains, “A spring freeze event is very bad because plants have begun to grow, or their buds have started to swell and are less cold hardy.” The line between “rough” and “disaster” on those days is razor thin. In apples, the difference between a frost that causes a 10 percent bud loss and one that loses 90 percent can be under 10 degrees’ difference, held for just a half-hour.
While I vaguely knew all of this, it’s not something that I think about very often. Like most people, I expect, I view the weather in terms of how it impacts me and my family–how to dress, what activities to pursue, and so forth–rather than how it impacts the agriculture industry. Obviously, farming effects my life, too, but less directly.
Then again, a much warmer than average winter benefits humans in ways other than the trivialities of dressing in lighter clothing and enjoying more outdoor activities. I don’t have any way to quantify this but I presume that a lot fewer people die from weather-related issues when it’s 55 degrees out than when it’s 35 or 95. Extremes of temperatures kill people without the resources to artificially control the temperature.