Detailed Explanation of Key Techniques for Outdoor Winter Cuttage Propagation of Roses
1. Treatment of Flower Cuttings
From mid-October to early November, in conjunction with winter pruning of roses, select branches with uniform internodes and plump dormant buds, remove the leaves, and cut them into 10 cm long cuttings (about 3 nodes). Cut the upper end into a flat cut and seal it with paint, and cut the lower end into a slanted cut for later use.
2. Preparation of Flower Seedbeds and Nutrient Bags
Select a plot that is sheltered from the wind, facing the sun, flat in terrain, and with loose soil, and make a seedbed 1 m wide, 5-6 m long, and 20-30 cm deep. Mix decomposed nutrient soil and fine sandy soil in equal halves to make moisture-balanced nutrient soil, disinfect it with phoxim and carbendazim, and then put it into nutrient bags for later use; alternatively, it may be spread directly on the seedbed without nutrient bags.
3. Flower Cuttage Propagation
When inserting, place the nutrient bags one by one on the seedbed. Make holes with a wooden stick or chopsticks, then insert the cuttings to a depth of 1/2-2/3, and press firm. Note: do not insert them upside down; the prickles should face down and the buds should face up. Water while inserting, and water thoroughly after insertion is complete. Then, prop up wooden sticks on the seedbed, cover with plastic film, and press the edges down with soil.
4. Management After Flower Cuttage Propagation
4.1 After insertion, if the weather is clear and the temperature is relatively high, open the plastic film at both ends of the seedbed at noon for ventilation. Otherwise, sunscald is likely to occur, and large numbers may die in early spring. In mid-November, seal the plastic film tightly.
4.2 Watering and film removal: after watering thoroughly at insertion, do not water again afterward. If the soil surface turns white, water lightly as appropriate.
After winter begins, a frozen layer forms underground, and the seedlings do not lack water. At Yushui and Jingzhe, observe the seedbed temperature, and ventilate promptly when it is above 20°C; otherwise, the seedlings are very likely to be scorched. Remove the plastic film gradually as the young seedlings unfold their leaves.
4.3 Pest control: from late March to early April, when the cuttings' buds are about 1 cm long, they are prone to aphid damage. Attention should be paid to preventing aphids. Fumigation with 80% dichlorvos may be used, that is, place five medicinal cotton balls with a diameter of about 0.6 cm per 2 sq m, and remove them after 2 hours. Observe after 1 week, and place them again if there are still insects. At this time, special attention should be paid to pests; otherwise, the harm to the seedlings is extremely great.
5. Precautions
For winter flower rose cuttage propagation, cold seedlings are afraid of heat, so after spring begins they can no longer be placed in a greenhouse. In April-May, pot them or plant them in the ground, and carry out normal maintenance.