Rubber Plant Propagation Methods and Key Cultivation Techniques
The rubber plant, also known as Indian rubber tree or gum fig, is an evergreen tree of the genus Ficus in the mulberry family. It is tall and robust, reaching a height of up to 30 m. Its leaves are large, oval, leathery and glossy, densely arranged in an alternate pattern. Because the leaf stalks are slender, the leaves droop slightly, which is why it is also called the weeping rubber plant. Common varieties include: golden-edged rubber plant, with golden-yellow leaf margins; variegated rubber plant, whose leaves bear many irregular yellow-white patches; white-spotted rubber plant, whose leaves bear many white patches; red-bracted rubber plant, with thick, deep green leaves tinged with red and red bracts; yellow-spotted rubber plant, with green leaves bearing irregular yellow-green spots; pretty-bracted rubber plant, with deep green leaves and both the midrib on the underside and the bracts bright red; beautiful-leaved rubber plant, whose new leaves are pinkish and whose mature leaves are deep green near the midrib and milky white around it; golden-star broadleaf rubber plant, whose young leaves are reddish-brown-green and turn reddish-brown as they mature.
It is usually propagated by cuttings and air layering, chiefly by cuttings; both softwood and hardwood cuttings root readily. Each section should have 3-4 nodes, with the lower leaves removed and the top two leaves tied together to reduce transpiration. The cut end is sealed with plant ash or clay to prevent the milky sap from flowing out. Cutting in months 1, 5 and 9 is best, as the summer heat easily causes cuttings to rot. The best rooting medium is river sand mixed with peat. Insert the cuttings to a depth of about 1/2, place them under a shade frame, and keep them at an optimum temperature of 25°C; they will root in 4-6 weeks and can then be potted. Weak species or horticultural varieties can be propagated by layering: make a ring of bark removed on the trunk, wrap it with moss kept moist, and roots will form in about 3-4 weeks; then cut it off and pot it up. Water propagation can also be used: tie 10 cuttings together, insert one third of their length into water, change the water once a day, and they will root after 50 days.
The rubber plant likes high temperatures, high humidity and sunlight. Temperatures above 25°C are extremely favorable for growth. It is also fairly cold-hardy and can overwinter outdoors in the Fujian and Guangdong areas. Generally, an overwintering temperature above 3°C is sufficient. Its leaves are thick and leathery and can withstand fairly strong sunlight. However, direct strong sunlight in summer will cause the leaf surface to lose its gloss. Placing it in too shady a spot will cause leaf drop. When kept indoors, choose as bright a spot as possible. It grows rapidly and has a high fertilizer demand. For potting soil, it is best to use a half-and-half mixture of garden soil and leaf mold, with some base fertilizer placed at the bottom of the pot. During the growing season, apply liquid fertilizer once a month. When ventilation is poor, powdery mildew and brown spot disease are likely to occur.
Diseases include anthracnose, leaf spot and gray mold, which are controlled by spraying a 500-fold dilution of 65% zineb; pests include scale insects and thrips, which are killed by spraying a 1000-fold dilution of 40% omethoate emulsifiable concentrate.
The rubber plant is a large evergreen foliage plant, green and flourishing all year round, handsome and elegant, and is a common courtyard tree and potted ornamental plant. In the Guangxi and Fujian areas it can be planted as a street tree or courtyard tree; in northern gardens it is mostly grown in pots as a focal display. Medium and large potted plants can be placed on both sides of the entrance halls of large buildings and on plazas during the growing season, arranged as flower beds. In winter they can be placed in lobbies for decoration.
How is the rubber plant propagated and cultivated?
How is the rubber plant propagated and cultivated?
The rubber plant is generally propagated by cuttings and layering. For cuttings taken during the spring and summer growing season, choose vigorous two-year-old branches from the middle and upper parts of the plant as cuttings. For autumn cuttings, choose woody branches of the current year as cuttings. As long as the bed temperature can be kept above 15°C during rooting, there is no restriction on when to take cuttings. Besides bed cuttings, water propagation can also be used. In April and May, take 15 cm-long branches of the current year, remove the lower leaves, let the cut end dry, then insert it into a glass bottle filled with water, place it in diffused light, change the water once a week, and roots will form in about 1 month.
In South China the rubber plant is grown outdoors as a landscape tree, while in Guizhou Province it is mostly grown as a potted ornamental and for indoor display. To overwinter it indoors, a temperature of 5-10°C must be maintained. It is best to choose a slightly acidic potting soil rich in humus, loose and fertile, with good aeration, and to pot it up or repot it before the autumn Frost's Descent or before bud break in spring.
Adult plants are repotted once a year; when repotting, cut off the crooked roots and add fertilizer, and during the growing season apply a nitrogen-based liquid fertilizer twice a month. Keep the potting soil moist at all times, pay attention to watering during the spring drought and the dog days and mist more than twice a day, but take care that the potting soil does not become waterlogged. In autumn and winter, control watering and do not water until the potting soil is dry. When the plant grows to about 80 cm, pinch out the growing tip to encourage side branches. For branches 80-100 cm long, cut them back at a plump bud so that more branches sprout and a full, rounded crown forms. When the plant is 6 years old, it can be moved into a wooden tub or large vat; there is no need to repot, only to change the soil, add base fertilizer and cut off the crooked roots.
Related content on how to grow the rubber plant:
How to grow the rubber plant and points to note
Cultivation and management of the Indian rubber tree
How to plant the rubber plant
How to grow the rubber plant
How is the rubber plant propagated and cultivated?
The rubber plant is generally propagated by cuttings and layering. For cuttings taken during the spring and summer growing season, choose vigorous two-year-old branches from the middle and upper parts of the plant as cuttings. For autumn cuttings, choose woody branches of the current year as cuttings. As long as the bed temperature can be kept above 15°C during rooting, there is no restriction on when to take cuttings. Besides bed cuttings, water propagation can also be used. In April to May, take 15 cm-long branches of the current year, remove the lower leaves, let the cut end dry, then insert it into a glass bottle filled with water, place it in diffused light, change the water once a week, and roots will form in about 1 month.
In South China the rubber plant is grown outdoors as a landscape tree, while in Guizhou Province it is mostly grown as a potted ornamental and for indoor display. To overwinter it indoors, a temperature of 5-10°C must be maintained. It is best to choose a slightly acidic potting soil rich in humus, loose and fertile, with good aeration, and to pot it up or repot it before the autumn Frost's Descent or before bud break in spring.
Adult plants are repotted once a year; when repotting, cut off the crooked roots and add fertilizer, and during the growing season apply a nitrogen-based liquid fertilizer twice a month. Keep the potting soil moist at all times, pay attention to watering during the spring drought and the dog days and mist more than twice a day, but take care that the potting soil does not become waterlogged. In autumn and winter, control watering and do not water until the potting soil is dry.
When the plant grows to about 80 cm, pinch out the growing tip to encourage side branches. For branches 80-100 cm long, cut them back at a plump bud so that more branches sprout and a full, rounded crown forms. When the plant is 6 years old, it can be moved into a wooden tub or large vat; there is no need to repot, only to change the soil, add base fertilizer and cut off the crooked roots.