Transplanting plants at a certain point is essential and something everyone will encounter. Our goal is to help beginners have a solid understanding of how to approach this process. You’ve likely already seen some related videos online and read about various techniques. You may have also heard of cases where plants die due to repotting. Yes, improper methods or concepts can lead to such outcomes, but isn’t it true that if care isn’t right, plants could die even without repotting? Therefore, repotting isn’t something overly serious. The main focus is to observe the plant’s condition for the first two weeks after repotting. This is the most important part – if any issues arise, you’ll catch them quickly and address them.
Step 1: Remove the Original Medium
Carefully remove the plant from the old pot (it may be unavoidable or unintentional to break a root. Don’t panic, as it’s already done – just look ahead). Please keep in mind, don’t wait until the medium is completely dry before repotting; the best time to repot is when the original medium is still damp.
Repotting Different Mediums
Concept:
Different mediums have very different water retention abilities. The goal is to remove as much of the original medium as possible from the roots, so that the roots can be in the same level of moisture, increasing the chances of success. Moreover, when transferring the roots from their original environment to a new one, some roots may rot, but as long as the plant remains healthy and vibrant, it’s not a major issue. Plants also undergo metabolic changes, and even without repotting, old roots may still rot. As long as the plant continues to grow normally, doesn’t show signs of dehydration or severe rot, the rest can be left to time.
(Please note that Pon and other popular potting mixes are considered different mediums)
1. If the original medium is water propagation or semi-hydroponics like LECA
The new medium can be any type. Water propagation or semi-hydroponics like LECA should only be repotted once the roots have exploded (grown extensively). For beginners, make sure that the container has roots growing along the walls before considering repotting. Ideally, you should see new roots growing in at least five different spots inside the container before repotting. The reason for this is that transitioning from water or semi-hydroponics to any other medium will result in some root damage because the growing environment has completely changed. Weak or less adaptable roots will inevitably rot. Therefore, it’s best to wait until the root system is robust, so even if some roots are sacrificed, the remaining healthy roots can continue growing, significantly improving survival rates.
After completing this step, proceed to Step 2.
2. If the original medium is sphagnum moss
The key point is to remove the moss as thoroughly as possible. Yes, we know it’s difficult, but it’s crucial. When a plant adapts to a new potting mix, it will adjust its water absorption. If remnants of moss with different water retention properties are left on the roots, it could cause some roots to absorb too much water while others absorb little. This uneven water distribution can cause root rot. Sphagnum moss has a strong water-holding capacity and can continue to supply water to the roots, which leads to excessive moisture at the root areas and eventually root rot. Therefore, we recommend removing as much moss as possible. However, a tricky point here is that removing the moss may harm the roots. Even if it doesn’t appear visibly damaged, the plant’s tissues could be affected. It depends on technique and experience, but aim to minimize damage.
Once you’ve removed the moss, proceed to Step 2.
3. If the original medium is soil
Carefully remove the plant from the pot. Since most soils are loose, gently shake the plant, and most of the soil should fall away. Then, carefully manually remove any remaining medium.
Once done, proceed to Step 2.
Repotting the Same Medium (New Medium is the Same or Similar to the Old One)
(Please note, Pon and other mainstream potting mixes are considered different mediums)
After removing the plant from the pot, gently shake it to remove any loose outer medium or unnecessary parts. If there are any rotting roots, they should fall away naturally. In some cases, it’s hard to see the internal root condition due to the medium. If nothing falls off during shaking, it’s not a big deal. The main point is to ensure that no severe and obvious root rot is present.
Proceed to Step 3.
Step 2: Inspect the Roots
In the previous step, you may have damaged some roots or found rot. If roots are broken but haven’t fallen off (yet), remove the broken parts immediately, as they will not regenerate. Leaving them in the pot may increase the risk of further rot. Remove all rotting roots. Check for any discolored areas and mushy area. If you find blackened, mushy spots, cut the roots approximately 0.5 inches above the rotting area, and continue cutting upwards if necessary until there’s no sign of rot.
Once done, proceed to Step 3.
Step 3: Choose the Right Pot
Choosing the right pot size is crucial. Selecting the wrong size pot can cause stunted growth or root rot, and may even lead to the plant’s death. The basic concept is that a bigger pot isn’t always better. Don’t think that a larger pot will help retain more water and reduce watering frequency. Similarly, don’t choose a smaller pot to restrict root growth, thinking it will limit the plant’s size. Both of these approaches can cause stunted growth, root rot, or worse outcomes. Remember, the pot size should be based on the root system and condition, not just the plant’s size or leaf size !!!
Generally, if the old pot is filled with roots, choose a pot that is 2 inches larger than the old one. If the old pot is root-bound and roots are growing out of the pot, assess the situation and choose a suitable pot.
The method is to place several pots of different sizes next to the plant, then put the plant (without potting mix) inside the pot to compare. Once the plant’s roots are inside, there should be about 1/4 to 1/3 space left in the new pot. This is the ideal size. Don’t worry about precise measurements – just aim for a pot that isn’t too big.
Continue to Step 4.
Step 4: Repotting
Once the pot size is confirmed, add a small amount of new medium to the bottom of the pot. Place the plant in the pot. Don’t worry about the plant’s height at this point (it’s better to place it lower). Arrange any roots that are growing out of the pot carefully, but be gentle as some roots are soft and brittle. Make sure not to damage the tips of new roots. Gently push the plant into the pot, then fill in the potting mix. Hold the main stem with one hand while lightly tapping the outside of the pot with the other hand. While tapping, gently pull the plant upwards until it’s at the desired height (be gentle and slow, don’t rush). Once you reach the right height, fill in any gaps with potting mix. After that, water the plant.