How to control the flowering period of peonies? Practical measures and key techniques
The flower bud differentiation period of peonies generally begins in June and basically ends by the end of September; in double-flowered and semi-double-flowered varieties, differentiation continues after September. When forcing blooms, first select appropriate varieties, such as 'Zhao Fen', 'Er Qiao', 'Zhu Sha Lei', 'Si Fen He', 'Jin Pao Hong', 'Luoyang Hong', etc., and at the same time select 4-5 year old plants with many plump buds and vigorous growth. Strengthen water and fertilizer management, apply foliar topdressing during the flower bud differentiation period, and select and retain strong branches and buds.
They can be placed in a cold cellar on July 15 and kept at about 0-2°C for cold storage to promote early dormancy. After half a month, take them out of the cellar and place them in a cool, semi-shaded place, and spray water on the plants and around the flower pots so that the plants resume growth. After the buds sprout, gradually increase light, and every 7-10 days apply a dilute cake fertilizer solution, or use 0.1% potassium dihydrogen phosphate for foliar fertilization. After September 25, keep the temperature at about 22%, and they can bloom by the end of September.
Alternatively, in early August, cut off all leaves, leaving petioles 2-3 cm long, and apply one application of decomposed cake fertilizer to promote new bud germination. When the flower buds begin to sprout, gibberellin can be used to promote bud germination, assist stems, and set buds. The method is to wrap absorbent cotton around the buds, then from 8 to 10 a.m. every day, use a brush to apply 700-800 mg/kg gibberellin solution 3-4 times, which can promote uniform flower bud germination. After leaves unfold, spray a mixture of 0.1% urea and 0.2% potassium dihydrogen phosphate 2-3 times, and they can bloom successively in late September. If leaf removal is carried out in batches from late July to early September, flowers will open from early September to mid-November.
To make peonies bloom at New Year's Day (or Spring Festival), select excellent varieties 4-5 years old, pot them 45-60 days before New Year's Day (Spring Festival), move them indoors and gradually raise the temperature, controlling it at 15-20°C during the day and 10-15°C at night, and frequently spray water on the leaves and ground to increase relative humidity. After leaves unfold, gradually increase light, apply thin fertilizer every 7-10 days, and spray a 0.2% potassium dihydrogen phosphate solution on the leaves. In this way, after 40-45 days, at most 60 days (varying by variety), they can show color and open at New Year's Day (or Spring Festival). After blooming, appropriately lower the temperature and keep it at 10-15°C to prolong the flowering period.
To make peonies bloom on May 1, move dormant peonies stored in a cold storage room indoors at the end of March, gradually raise the temperature, and water, spray, and fertilize appropriately. Because the temperature is relatively high at this time, they can bloom after about 1 month.