What is Frost Heave?
When water turns into ice underground, it expands. This can make the ground move, causing frost heave. Frost heave lifts up the ground, as well as everything on top of it. Frost heave can be strong enough to move and damage roads, bridges, and buildings. Frost heave is especially strong where there is permafrost or deep seasonally frozen ground .
Frost heave is the result of pressure created from a combination of freezing temperatures and soil defrosting. The fluctuating freezing and thawing conditions heave, or lift, the soil, which is often characterized by deep cracking of the soil. Plants may be uprooted from the ground as well. For many gardeners, this can become a major issue, as entire crops can be lost or damaged. Plants can quickly dry out and die once their roots have become exposed to cold temperatures. This heaving of the soil can also cause structural damage, in the form of cracks, on roadways, buildings and foundations. This damage can range from minor to major depending on location, weather conditions and soil structure. While frost heave usually occurs in early spring, it can happen during late fall as well. This is when seasonal temperatures fluctuate most. Frost heaves are favorable whenever there is an abundance of cold air and soil moisture. Soil freezing results from this cold air, soil moisture combination
The continuous alternation between freezing and thawing can affect many solid structures such as pavement, concrete, and building foundations, but those solid inanimate objects will not die from what is known as frost heave. In the garden, frost heave can quickly destroy plants and small shrubs if steps are not taken to prevent this winter damage. For frost heaving to occur, the soil must have the ability to conduct water, an affinity for water, and high saturation; i.e., moisture retentive soils such as silt, loam, and clay. Additionally, a supply of water must be available and, lastly, freezing temperatures must be present. How and When Does Frost Heave Happen? Alternative freezing and thawing creates pressure which lifts the soil upward, usually taking the plant with it. Cold air penetrates down through the soil to the area of warmer soil and moisture, freezing it and forming a layer known as an “ice lens.” The cold air from above presses down while the frozen soil beneath the plant
