Thickets are generally a formation of wild shrubs grown together to form a mass of impenetrable branches. Some have thorns making them difficult to grasp and remove. Thickets can form anywhere land is left to its own devices and the shrubs most often found in thickets are very opportunistic and grab any chance created by man-made disturbance or natural disaster to produce a wall of shrubs.
A big difference between several shrubs planted close to each other, and a thicket is that the shrubs in a thicket are interlocked. The branches and roots tangle up to join them as if they were a single plant. This makes thickets nearly impenetrable to hikers or passersby. Thickets are the most difficult type of landscaping for wilderness hikers to conquer. They usually mean re-routing to circumvent the area.
Thickets are not overly tall and do not grow larger than 20 feet, with 10 foot being the most common shrub height. The individual plants are average width, but the combination of many plants can stretch a thicket out for miles. They are a mid-level plant, smaller than trees and larger than ground cover plants.
Creation and Control
Thickets are common in swamps and wetlands. Other occurrences contribute to the formation of thicket shrubs. Man-made disturbances such as logging, construction that impacts the water table, or natural disturbances like earthquakes and tornadoes create hospitable environments for thickets. The soggy land surrounding riverbeds where flooding occurs often is a likely place for thicket formation. Nature naturally maintains this type of thicket at a reasonable level when the river floods at regular intervals.
Thickets provide a small ecosystem for local wildlife. They provide food in the form of berries or flowers, shelter and ground cover. In some areas, state conservation laws protect thickets. Always check before attempting to remove or trample a thicket. Thickets create valuable cover for cottontail rabbits, whitetail deer, beavers and snowshoe hare, and birds especially enjoy the variety of seeds and berries created by the shrubs.
Common Thicket Shrubs
The type of shrub you will likely find in a thicket depends a great deal on the climate of the area, and how the thicket formed. Wood nettle, wild ginger and swamp buttercup thrive in the wet, soggy river or floodplain thickets. Horsetail, switchwort and Twinberry opportunistically take advantage of man-made shifts in the natural order of plants and form quick thicket walls that prevent other plants from forming. Blueberry, olive and wild plum are common plants on residential properties allowed to overgrow. The thorny shrubs such as blueberry are difficult to get rid of without burning to the ground.