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February 13, 2019
Definition: A barrier of tall and short trees or shrubs planted to slow the movement of wind at crop level and divert the force of the wind to higher altitudes. Planting multiple rows along a field or garden minimizes the amount of moisture winds evaporate from the soil and blocks winds from disturbing crops and eroding topsoil.
In the Forest Garden: When farmers establish windbreaks to protect their Forest Gardens from strong winds, one of the most important considerations they must account for is spacing. Windbreaks are designed to slow, but not completely stop the wind from penetrating the field, if a farmer spaces his rows of trees and shrubs too densely, the barrier creates strong air currents above the field that will damage crops and erode soils. A proper windbreak should be 50% permeable. At the same time, farmers must also make sure that they leave no major gaps when spacing out their windbreaks as this can create tunnels of high-velocity winds that could devastate a field.
When done correctly, a windbreak can protect for a lateral distance of up to ten times the height of the tallest trees. So five-meter-tall trees provide protection extending 50 meters beyond the tree line, as long as the windbreak is uniform in height and spacing among trees.
Windbreaks vs. Living Fences: A windbreak is not part of a living fence. The living fence is typically smaller and surrounds the entire perimeter of a Forest Garden. A windbreak includes taller trees and is usually built on the side of the field receiving damaging winds.