Flowering of tree peony (Paeonia suffruticosa, Andr.) in the early summer and in the middle autumn by short- or long-term cold-storage were examined.
Plants stored at -2℃ from February 13 to April 11 and May 11 flowered in the middle of May and in the early June, respectively. The former showed high flowering rate while the latter, rather low rate expect one cultivar. Flowerquality in retarded culture was low, especially in flowers in the early June.
Although some cultivars stored at -2℃ to September 20 flowered in the late October,their flowering rate and flower quality were very low.
Retarding of tree peony would be possible commercially only by short-term storage for May flowering.