Borders around farmland form a significant niche in which trees may be planted. Traditionally farm borders have been heavily exploited for tree planting by farmers. Borders include those with neighboring lands, internal boundaries that sub-divide the farm, and borders around the house. As farm borders typically include unproductive land, tree planting in this niche can increase overall farm outputs. Three categories are discussed below: 1) Hedges and 2) living fences are kept pruned low and have less direct influence on adjacent farmland. 3) Windbreaks are allowed to grow to larger sizes, and influence a larger portion of the farm land.
Trees for hedges are planted very close together. For example, a typical planting is with trees in double rows 0.5 meters apart, with trees also 0.5 meters apart within the rows. Hedges require frequent trimming to the desired form (height, width, and shape) to encourage secondary branching, and thus an impenetrable hedge.
NFT genera of particular importance for hedges include Acacia, Pithecellobium and Prosopis. The species of importance in these genera are typically thorny, a particularly good characteristic for keeping out large animals. Casuarina also can be formed into a thick hedge.