A bedding foundation having a nestably stackable spring assembly, including a border wire. The foundation's spring assembly may be nestably stacked with numerous other such assemblies for transportation, thereby avoiding the need to compress and tie the assembly for shipping. Each spring assembly includes support wires having alternating peaks and valleys along with stabilizer wires having alternating peaks and valleys. The valleys of the stabilizer wires are secured to the valleys of the support wires. The peaks of the stabilizer wires are secured to longitudinal wires extending parallel the sides of the border wire.