French colonists planted their vineyards in the highlands areas around the Ba Vì mountain range near Hanoi. Modern viticultural techniques have produced some successful results with aggressive pruning and the adoption of the pergolas style of trellising. This Pergolas trellis has the benefit of keeping the grapevines off the ground to where some of the humidity is ventilated which reduces the risk of powdery mildews developing. The grape bunches are shaded by the canopy of the vine which reduces the yields.