In 1994, the Festival was expanded to two weeks to accommodate the many activities that happen during the trees' blooming. Two years later, the Potomac and Arakawa became sister rivers. Cuttings were taken from the documented 1912 trees in 1997 to be used in replacement plantings and thus preserve the genetic heritage of the grove. In 1999, fifty trees of the Usuzumi variety from Motosu, Gifu, were planted in West Potomac Park. According to legend, these trees were first planted by Emperor Keitai in the 6th century and were designated a National Treasure of Japan in 1922. From 2002 to 2006, 400 trees propagated from the surviving 1912 trees were planted to ensure the genetic heritage of the original donation is maintained.