What false spring is and why it is dangerous for plant growth
If you have taken a look at the forecast over the next 7 days, the temperatures might have caught you by surprise. By Monday, afternoon high temperatures will be in the low 60s, and morning temperatures will be staying above freezing. You might think that spring has come early, even with us not being through the first week of February yet, but this weather can be deceiving. This is not just a warm spell; it's what is known as "false spring."
This is all because of the upper air pattern. The polar jet stream that has been positioned over Central Missouri and has been allowing frigid air into the region is getting pushed out because of a high-pressure system to the west. As this high-pressure system continues to shift closer to Central Missouri, colder air will be forced out of the area, and warmer air from the south will be allowed back into the region. This is why temperatures will be climbing to a noticeably higher number by the start of next week.
These much warmer and well-above-freezing temperatures are where the main danger lies for plants. Plants have an internal clock called "chilling hours." By February, most plants have slept enough, so the warmth acts as an alarm clock for the plants to wake up. As this happens, the plant's de-acclimation phase starts, which consists of trees and plants pushing water from their roots to their buds to start blooming. Once this occurs, they lose their natural anti-freeze, leaving them awake, vulnerable, and defenseless. This damages the buds, making them less likely or unable to go through any more production.
Missouri certainly is not done with the winter weather yet, as it is almost guaranteed that there will be more freeze opportunities throughout the rest of February. The likelihood of a freeze is still very high throughout March, and although lower, the chance still remains for the beginning of April.
On average, Missouri experiences its very last freeze any time from April 1st through April 15th, so that means there is still well over 2 months until the last opportunity for this to happen is even in consideration. Although it is tempting to start planting or bring out plants in this weather, it is important to keep them indoors, as even one freeze can harm them.
Even though it might not be the best time to put plants outdoors, it is still a great time to enjoy the weather yourself before the next cold snap arrives. At least one more wave of winter weather will likely be in the forecast, so getting out to take in the afternoon temperatures that are almost 10 to 20 degrees above average this weekend and next week may be a nice change of pace!
