How to Divide and Propagate Orchids When They Outgrow Their Pot? A Detailed Guide to Practical Techniques
Growers who cultivate orchids know that after several years of growth, an orchid will inevitably become a large clump, and at that point it needs to be divided. The key to dividing is really the separation of offsets. So how do you divide a potted orchid? Let's take a look together at the techniques for propagating orchids by division.
I. Conditions and Timing for Orchid Division
1. Conditions for orchid division: Division is usually carried out after two or three years of growth, when the orchid plants have already filled the entire pot; it is also done to increase the germination rate, or to rapidly increase the number of propagated varieties, by dividing connected orchid clusters with 4 or more plants; and it is also done to prevent the degeneration of bud-sport odd plants, by dividing a connected parent-and-child cluster consisting of just one old and one new plant.
2. Timing for orchid division: Orchid propagation by division can generally be carried out in all four seasons, but to ensure the survival rate, it is usually done when the temperature is between 12°C and 30°C. According to its physiological characteristics, the best time is at the end of the flowering period. This is because at this time the orchid plant's vegetative growth has slowed, not only have new buds not yet sprouted, but even the growth points of the buds have not yet swollen, so division is unlikely to cause accidental damage. At the same time, the flowering period has ended, so generally no more flower buds will grow, and there is no problem of damaging flower buds through division. In addition, division can also promote active vegetative growth and increase the orchid plant's ability to rejuvenate and its germination rate.
II. Key Technical Points for Orchid Propagation by Division
1. Lifting the plant.
When dividing and repotting, the potting soil should be somewhat dry. If the potting soil is too wet, the operation is inconvenient and the fleshy roots are easily broken and injured. When repotting, after turning out the mother plant, gently remove the soil clumps and shake the substrate out of the root ball. If the substrate is compacted or sticky, rinse it apart with water before dividing the clusters.
2. Washing the roots and drying the roots.
It is best to wash the roots with running tap water; soaking in water can easily spread diseases and pests. After the substrate is washed off, spread the orchid plant in sunlight and cut off rotten roots and broken roots. Rinse the roots and leaves clean with water, then dry them until the orchid roots become soft, and use scissors to cut at the pseudobulb where the gap is large. Coat the cut with charcoal powder or sulfur powder to prevent infection by pathogens, then wait to plant.
3. Choosing the pot. How well an orchid pot is ventilated and breathable directly affects how well the orchid grows. Generally speaking, clay pots have the best ventilation and breathability, purple-clay pots are next, and porcelain pots are the worst. When using a new clay pot, note that it should first be soaked in clean water for 3 days, then soaked in disinfectant water for 2 hours, and used after drying. For orchids that are more difficult to grow, clay pots are more suitable; if they need to be decorated indoors or displayed at a venue, a porcelain or glazed pot can be placed over the clay pot, and the bottom of the pot must be filled with relatively coarse material to ensure ventilation and breathability.
4. Dividing and potting up.
When potting up an orchid, the filling layer generally accounts for 1/4 of the orchid pot's height, while the length of the root mass is best at 1/3 of the orchid pot's height, so an ideal orchid pot is generally taller than other flower pots. The width of the pot waist can be large or small according to actual needs; in short, the orchid roots must have enough room to grow.
Potted orchid plants are generally divided using two-generation or three-generation connected plants as a unit, planting an appropriate number of natural clumps depending on the size of the pot, then adding fine soil until it is 2 to 3 cm from the pot rim. Lift the orchid plant slightly so that the roots spread out naturally, with the lifting height based on the top of the pseudobulb being level with the soil surface of the pot; it must not be too deep or too shallow. Then shake the pot to make the soil and roots come into close contact. Press down firmly with your hand along the sides of the pot to avoid hollow spaces when watering.
5. Management after potting up.
Place a layer of lichen or broken tiles on the top layer of the flower pot, so that watering is less likely to cause the potting soil to compact, and to reduce evaporation of moisture from the potting soil. For the first watering, it is best to use the sit-in-water method, that is, place the potted orchid pot in water with the pot surface exposed 3 to 5 cm above the water, so that water slowly seeps upward from below. When the water has seeped up to the soil surface of the pot, take the orchid pot out of the water and place it in a shaded place for about 15 to 30 days, without direct sunlight. During this period, watering must be controlled and it must not be too wet. Afterwards, move it to a place with half shade and half sun, ventilated and breathable, where it can get morning sun. Whether cultivated on a balcony or in a courtyard, it is best to place the flower pot on an orchid rack that is open to the air on all sides; an enclosed balcony should have sliding windows. This is very beneficial for reducing orchid pests and diseases.
That is all for our introduction to orchid propagation by division. Division propagation is asexual reproduction and is the most traditional propagation method, with the advantages of simple operation, a high survival rate, rapid increase in plant numbers, earlier flowering, and ensuring quality characteristics.
Reference on Autumn Orchid Repotting and Division Methods and Steps
Potted orchids on the balcony
During a holiday I visited a friend's home and saw the balcony filled with orchids. I was very envious, so I asked my friend how this was done. My friend said that in addition to the usual careful care, you also need to do a good job of repotting and dividing in autumn, so that you can add a few pots of orchids every year. So that's how it was. I asked about the specific methods, and here I will share them with everyone.
Late autumn is one of the best periods for orchid repotting and division. If handled well, it can not only propagate small orchids, but also be very beneficial to the orchid's flowering and growth the following year. Therefore, orchid growers should attach great importance to autumn repotting and division work.
Precautions for orchid repotting and division:
① Before repotting and division, the potting soil should be slightly dry to prevent damaging the orchid roots;
② Division tools such as scissors or a sharp knife must be disinfected.
③ The cuts from orchid division and the wounds from trimming the roots must be coated with sterilizing powder or plant ash to prevent wound infection;
④ The division site should be clean, and the water used to wash the orchid plants must be hygienic. Never use one basin of water all the way through; it is best to rinse with running tap water; after washing, the orchid plants must never be exposed to strong sun, and should be placed in a shaded place to dry.
⑤ Because the pseudobulbs of cymbidium orchids are too small and store limited nutrients, division should not be too frequent; generally it is best to grow 4 to 5 connected plants together. Except for individual strong plants with good root systems and a natural “pathway” for starting growth, single-plant cultivation is generally not advisable;
⑥ As long as the orchid pseudobulbs are plump and full and the root system is well developed and intact, strong starting plants can absolutely be cultivated as single plants. If 4 to 5 generations are “living together in the same house,” it is instead detrimental to growth, and timely division is necessary.
Generally speaking, after more than two years of cultivation, most of the nutrients in the growing medium are exhausted, so it is time to repot and replace the medium in a timely manner, so as to meet the orchid's growth needs; however, for weak seedlings the interval between repotting can be appropriately extended, because repotting too frequently is instead detrimental to the orchid's rejuvenation.
It is now autumn, and orchid growers can choose the right time to start repotting and dividing according to the different temperatures in various places. The above is only for reference; specifically, you still need to operate according to the actual situation of your own orchids, so as not to achieve the opposite of what you intend.