What are the propagation methods for the rubber tree?
The rubber tree is mostly propagated by cuttings. Cuttings can be taken in summer in conjunction with pruning, and the cuttings are best taken from two-year-old, semi-lignified middle branches. The most suitable temperature for rooting is a daytime maximum of about 30°C and around 15°C at night. Roots form in about 20 days after cuttings are taken, and the survival rate can reach over 90%. The cuttings are best cut to retain 3 buds; remove the lowest leaf, and bind the upper two leaves together with plastic string to reduce evaporation from the leaf surface. Immediately after cutting, seal the cut with clay or plant ash to prevent too much milky sap from flowing out and affecting survival. After planting, keep the soil moist but not waterlogged, frequently sprinkle water on the ground to increase air humidity, and provide shade.
In addition, cuttings can also be taken in winter, using branches cut during shaping and pruning of new plants that rooted from cuttings taken that year, and taken indoors around New Year's Day, keeping the temperature above 18°C; roots will form in 2 months, and the survival rate for cuttings of one-year-old softwood shoots is about 60%.
The rubber tree can also be propagated by water cuttings, carried out in mid to late May. Select one-year-old branches with terminal buds as cuttings, 6-10 nodes per cutting, cut about 1 cm below the last leaf node, remove the lower two leaves, place the cuttings in a shady spot for 1-2 days, then use a sterilized blade to cut the cut end into a horseshoe shape, soak in 5% sugar water for 2-3 days, then place in clean water to soak; the container should be shielded from light to encourage the early formation of white nodular growths. Change the clean water every 2-3 days to prevent the cuttings from rotting.
The container can be placed directly on a sunny windowsill, which benefits photosynthesis, accelerates the differentiation of root primordia in the branches, and helps white nodular growths form sooner. Once white nodular growths appear on the submerged part of the cutting, remove the cutting from the water and insert it into a potting mix made of equal parts leaf mold, plain soil and sand, with a planting depth of 3-5 cm. Keep the potting soil moist at all times, and in about 20 days you will have a new plant.
How do you propagate a rubber tree by cuttings?
The rubber tree can only survive cuttings in a high-temperature environment, and the soil temperature should be kept constant and stable; the survival rate is highest when cuttings are taken from late May to mid June. Young softwood shoots tend to rot after cutting, while old branches do not easily form callus tissue after cutting and are difficult to root. On the large side branches of perennial old plants, small shoots often sprout from dormant buds; they grow slowly, have short internodes and carry terminal buds, and their tissue is relatively plump. Cutting them off from the base, close to the cortex of the mother branch, and planting them directly gives a high survival rate, and because they carry terminal buds, they also take shape relatively quickly.
When pruning a rubber tree, many long branches are cut off every year, and these can be used for cuttings. First cut off the tender tip of the long branch, then cut it into sections of 3 nodes each, and immediately seal the cuts with plant ash to prevent the milky sap from flowing out. At the same time, remove the lower leaves and keep one leaf at the tip, either rolling it into a tube and tying it with fine string, or cutting off 1/2 of it. Insert it 3-4 cm deep into the soil; too deep and it easily rots. Because it is planted shallowly and the remaining leaf is relatively heavy, the cutting tends to fall over, so it is best to insert a reed stem for tying and support.
How do you propagate a rubber tree by air layering?
Propagating a rubber tree by air layering has one notable advantage, namely that it is easy to succeed. Here is a description of the specific steps for propagating by this method.
Rubber trees can be propagated by air layering in both spring and summer. Before starting, prepare clay, fine string and plastic film. Then choose the branch on the mother rubber tree that will be used as propagation material. A suitable branch should be more than 30 cm long, and the bark at its base should already be lignified, that is, choose a branch whose base bark is brown rather than green as the propagation material.
Measuring down from the tip of the selected branch, remove the leaves at about 20 cm, then use a sharp knife to peel off a ring of bark about 1 cm wide at that spot, to a depth where the white wood is visible. After removing the leaves and peeling the bark, the wound will exude a sticky liquid the color of milk, which can be wiped away with toilet paper. Then take a lump of water-added clay the size of a fist and press it around the girdled part of the branch, wrap plastic film tightly around the clay ball, and tie both the upper and lower ends with fine string.
Move the mother rubber tree, together with its pot, to a place with ample sunlight and carry out normal care; afterward, at intervals, use a syringe to inject some water into the clay ball. After about 6 to 8 weeks, more new roots will grow at the girdled part of the rubber tree branch. At this point, use sharp scissors to cut off the rooted rubber tree branch, carefully remove the ties, plant it in a flower pot filled with plain sandy soil, and place it in a spot without direct sunlight for about half a month of care.
Mist frequently to keep it moist, then gradually switch to normal watering and let it slowly receive direct sunlight. After the new rubber tree plant has been in the flower pot for 6 weeks, you can begin to apply some diluted liquid fertilizer to it. At this point, you can use the new rubber tree plant propagated by air layering, which has already adapted to the external environment, to decorate your space or give to relatives and friends.