THUJA OCCIDENTALIS NIGRA, Dark Green Arborvitae Hardiness Zone: 2 Prices by Size: 3 ft., W.B. - $30.00 4 ft., W.B. - $40.00 5 ft., W. B. - $50.00 6 ft., W.B. - $60.00 7 ft., W. B. - $70.00 [Your browser doesn't support IFrames. Click here to find the USDA hardiness zone for your zipcode.]