Detailed Guide to Oleander Cultivation Techniques and Care Methods
Oleander (Neriumindicum), also known as willow-leaf peach, belongs to the genus Nerium in the family Apocynaceae.
I. Overview:
It has been appreciated by people since ancient times. Its leaves resemble bamboo. The pink-flowered varieties are full and gorgeous, while the pure white-flowered varieties are as bright and clean as snow. Because its flower shape closely resembles peach blossoms, it is named oleander. It has been designated as the national flower by the people of Algeria.
II. Ecological Characteristics:
Native to India, Iran and Afghanistan. It prefers a warm, humid environment with ample sunlight. It is relatively cold-tolerant, tolerant of waterlogged conditions, tolerant of partial shade and strongly resistant to air pollution. The optimal growth temperature is 20-30°C, and the winter temperature should not be lower than -5°C, otherwise leaf frost damage will occur. The soil should preferably be fertile, loose and well-drained sandy loam.
III. Propagation Techniques:
Cuttings and layering are commonly used for propagation.
1. Cuttings: Can be done in spring and summer. Cut 1-2 year old branches, 15-20 cm long. Soak the base of the cuttings in water for 7-10 days, keeping the water clean, and maintain room temperature at 20-30°C. Roots will form 15-20 days after insertion.
2. Layering: Use the mound layering method in spring and summer. After slightly scoring the base of the oleander, mound it with potting soil. In the following spring, cut it away from the mother plant and transplant with the soil ball.
IV. Cultivation Points:
It has strong adaptability. Choose fertile and well-drained soil; it grows rapidly. Keep the soil moist. Before new branches sprout in spring, shaping and pruning are needed. Remove leggy branches and weak branches, which can be cut off from the base. Thin out overly dense inner branches to make the plant shape full and attractive. Apply fertilizer once before budding and once before and after flowering. After winter arrives, reduce water supply to control plant growth and improve cold resistance. For potted plants, repot once every 2 years.
V. Pest and Disease Control:
Leaf spot disease and tumor disease commonly occur; spray with 70% mancozeb wettable powder at 600 times dilution. Pests include scale insects and aphids; spray with 25% buprofezin emulsifiable concentrate at 2000 times dilution.