How Do Orchids Reproduce? A Detailed Guide to Common Propagation Methods

Orchids are propagated by two methods: division and sowing. Because sowing is very difficult and requires a certain level of technical skill, division is commonly used for propagation. A brief description of each follows:

(1) Propagation by Division

Division is also called "division of plants" or "repotting." This is a relatively complex operation in orchid cultivation. The following points must be mastered for division:

1. Timing The most suitable time for division is around April or September, that is, around Qingming (Clear and Bright) and Qiufen (Autumn Equinox). (When repotting, the potting soil must be slightly dry; if repotting with wet soil, the roots are easily broken and damaged.)

2. Mother Plant For division, first select a robust and disease-free mother plant. Also note that Cymbidium goeringii (Spring Orchid) must have four or five pseudobulbs of leaves, Cymbidium faberi (Faber's Cymbidium) must have eight or nine pseudobulbs of leaves, and Cymbidium ensifolium (Golden Thread Orchid) must have thirty or forty pseudobulbs of leaves before division is possible. Generally, orchids should be divided once every two or three years; dividing too frequently is not advisable, as the new leaves produced after frequent division are not easy to grow large, and the newly repotted surface soil cannot firm up quickly. Once rain falls, the floating mud sticks to the leaves, often causing disease.

3. Root Pruning After selecting the mother plant, gently turn the orchid plant out of the pot, remove the soil clumps, and carefully trim away dead roots and damaged leaves with small scissors. When pruning, the scissors must be used horizontally, not vertically, to avoid injuring young shoots. After pruning, rinse the roots with rainwater (that is, stored rainwater), place in a cool place, and wait until the root color turns white and the roots appear dry before dividing and repotting. If the weather is humid, wait until the roots are half-dry, then expose them to sunlight for more than ten minutes, and then let them dry in the shade. After the roots are shade-dried, select the gap in the middle (commonly called the "horse road") and cut through with sharp scissors. When cutting the roots, if many old roots are found, several should also be cut away to avoid hindering the development of new roots.

4. Potting Once the roots have been cut apart, potting follows. The bottom of the pot must have a hole for ventilation and drainage. The hole should be covered with several layers of clam shells, overlapping alternately to form a cone shape. Although tiles and the like can also be used, they are too heavy and inconvenient to move, so they are not suitable. If the hole happens to be too large, a cone-shaped net made of thick lead wire, about 7~8 cm high, can be used, with a layer of palm fiber placed on top; this can last more than ten years without breaking. There are also nets made of bamboo strips in a pointed-hat shape, but these generally last only about one year. After the clam shells and palm net are arranged, they must be tight with no gaps. Then fill coarse sand around the clam shells to a thickness of about 1 cm. On top of the coarse sand, add coarse soil or fine soil, with the thickness determined by the size of the plant's root system and the depth of the pot. Generally, 5 cm can be filled for Cymbidium goeringii and about 3 cm for Cymbidium faberi. Press the center of the soil surface with your hand to make it bulge like a steamed bun.

After filling with soil, finally place the divided orchid roots into the pot, arrange the roots well, and let them assume their natural state. Then fill fine soil around the pot again until it is about 2~3 cm from the pot rim, while also lifting the plant slightly upward. When pressing the soil, use your fingers to push soil from all sides into the root area so that all roots can contact the soil without leaving any gaps. It must be remembered that "if one root does not touch soil, that root will be empty." Therefore, the soil in contact with the roots should be very firm so that it does not sink, but the soil at the pot edges may be somewhat loose. At this point, plants such as Selaginella uncinata should also be spread on the pot surface as a protective ground cover.

After potting, water thoroughly and place in a shaded place facing north for about half a month to one month, avoiding sunlight, so that rooting and establishment occur easily. Once the soil surface gradually firms up and the Selaginella uncinata has also established, the orchid pot can be moved outdoors.

To maintain the vigor and a certain capacity for development of cymbidiums, small plants that have just begun to produce leaves, whether Cymbidium goeringii, Cymbidium faberi, or Cymbidium ensifolium, generally do not undergo this full repotting method. It is sufficient to use the original soil from other pots for sleeve-potting once every one or two years, which more easily achieves the goal of promoting flowering.

Sleeve-potting method: Generally, orchids are cultivated in three sizes of pots with different rim diameters according to the size of the root system. Newly divided plants are generally potted in pots with a rim diameter of about 15 cm; as they grow, they are successively sleeve-potted into pots with rim diameters of about 22 cm and 27 cm. Large clumps of Cymbidium ensifolium can be sleeve-potted into large pots with a rim diameter of about 40 cm. When sleeve-potting, first use your right hand to press the soil at the pot edge several times, then use your left hand to hold down the surface soil of the pot, tip the pot downward, and use your right thumb to push the soil inside the pot around the clam shells through the bottom hole, so that the plant with its soil can be tipped out of the original pot. After the plant is tipped out, all the soil must be placed intact into the new pot. Finally, add new growing medium around the original soil, spread Selaginella uncinata, press firm, and water thoroughly.

Although orchids are potted flowers, after division they can also be planted directly in the open ground for propagation.