Detailed Explanation of Key Techniques for Forcing Tree Peonies to Bloom in Autumn

If flowers are wanted to bloom in early October, defoliation should be carried out in late July. Spray the leaves with 2000 ppm ethephon, and the leaves will turn from green to yellow and gradually fall off. Any leaves that have not completely fallen can be sprayed again after 3 days, or simply cut off.

After the tree peony plants have been defoliated, the dormancy-breaking treatment can be advanced or delayed according to the time the flowers are needed.

Two methods are used to break dormancy in tree peonies:

1. Hormone treatment for flowers. The treatment time should be determined by the time the flowers are needed, and should be about 50 days in advance. Wrap each flower bud with a ball of absorbent cotton the size of a soybean, then use a brush to drip 500-1000 ppm of 920 onto the absorbent cotton. Do this once a day for 3-4 consecutive days, and the scaly buds will begin to swell and sprout. If the scales are dry, which is unfavorable for the absorption of the medicine, they can be peeled open with a small knife or removed before dripping the solution.

2. Low-temperature treatment for flowering tree peonies. This method is carried out 10 days earlier than hormone treatment. Dig out the plants; if the number is small, they can be planted in pots, and if the quantity is large, prepare wet sand or sawdust and place the plants in a cold storage room with the branches facing upward. After arranging one row, fill the gaps below the root crown with sand or sawdust. Arrange and fill row by row in this way, and do not leave the roots exposed outside. In the cold storage room, keep the temperature at 4°C-6°C for the first 7 days, then at 0°C-3°C for the next 7 days. After two weeks, take them out and pot them. In the early stage, it is best to place them under a shade shed. After 10 days, when the flower buds begin to sprout, move them into the sun for management.

Management During the Flowering Growth Period

For autumn forcing in the open field or in pots, the main approach is to use the autumn temperature and light conditions suitable for tree peony flowering, and no additional heating or warming equipment is needed. The management methods and steps are the same as the technical requirements for forcing in a greenhouse or plastic tunnel, and they can be used for mutual reference. However, note that pests often occur in autumn and bite new branches and young seedlings, so observe frequently and kill them promptly.

Plants forced to bloom in autumn, because their roots were not damaged, still grow vigorously the following spring, and some plants can continue to bloom. For plants that have been dug out and potted, after the flowers fade, since this is exactly the good planting period for tree peonies, they can be divided, the old branches cut off, and replanted.