Baby, It’s A Polar Vortex Outside!
We’ve been experiencing some very cold winter weather, with lots of frost or freeze damage possible in January. The difference between frost damage and freeze damage is that frost damage in plants results from the water in the cells forming sharp ice crystals and rupturing the cell walls. When the tissue thaws out, the water in the cells drains out through the new holes and the tissue dries out. Freeze damage occurs when temperatures sustain at 32 degrees or below and is progressive within plants. But, freeze damage to tender plants may occur much sooner. The softest tissues like leaves and tender new shoots are hurt first. Tougher stem tissue and buds down from the tips endure less damage, but are not immune if the temperatures are lower and the duration is longer, like it has been here in Middle Tennessee. Limp, dry and brownish leaves damaged by frost easily stand out, however damage to stems and buds can remain hidden for several months.
With extremely low temperatures a plants survival may depend on their stage of growth and development. Low temperatures cause far more damage than high temperatures. Temperatures below freezing can kill buds on fruit trees and damage the succulent twigs of most trees. Low winter temperatures may kill young tree roots or cause bark splitting and canker development. The degree of chilling and frost injuries depends on the duration of the cold temperatures and how fast the temperature dropped.
The extent of damage to plants depends on several factors including:
* Types of plant – Tropical plants have few internal protection mechanisms against freezing temperatures. Semi-tropical plants can handle temperatures slightly below freezing.
* Where it was propagated or its origin – Climate zone.
* Plant maturity and health – Perennial plants can withstand much lower temperatures once they are well established than when they were first planted. Generally, older more mature plants can typically tolerate freezing temperatures better than juvenile plants
* Fertilizing practices – Borderline plants may survive low temperatures if they are not pruned or fertilized with nitrogen after about August.
* Presence of late summer growth – Pruning may stimulate late growth and the new growth will not have time to harden off before the first frost
* The lowest air temperature achieved – Usually air temperatures decrease as the nights grow longer. If temperatures drop below freezing for a very short period of time, damage to tender plants is typically minimal. If the same temperature is reached, but maintained for several hours, freeze damage to plants is more severe.
* The month of the year freezing temperatures occurs – Freezing temperatures occurring early in the fall or late in the spring are usually more damaging to plants than freezing temperatures in mid-winter.
This January we had eight days where the actual high temperature was below normal and five of those days, the actual high was below our average low temperature for that day. We had twenty-two days with below average low temperatures and sixteen of those days the actual low temp was 10 or more degrees below average.
The good news is that spring is just around the corner. Take comfort in the fact that your trusted Nashvillle landscaping company, Perfect World Landscapes, LLC, is here. Once spring arrives, we’ll survey your landscaping with our many years of experience and vast plant knowledge and we’ll get your landscape just right!