Haworthia
The editor brings you some knowledge about the Haworthia genus (Haworthia), including issues related to the transplantation of Haworthia (Haworthia) seedlings, as follows:
A friend who is crossbreeding between Haworthia and万象 discussed the issue of seedling transplantation. He said that after transplanting, his seedlings developed thick roots and their growth significantly accelerated. However, my seedlings of the寿 genus showed a slow recovery and growth after transplantation. After an in-depth discussion, I found the problems with my寿 seedling transplantation.
The radicle of Haworthia is actually a weak juvenile root, which only ensures fixation and absorption (S-Y) needs during the early juvenile stage, and its own cambium is almost inactive, not turning into the later thick, fleshy roots. The 1-2 roots produced in the middle and late stages of the juvenile stage are similar to the radicle, both being thin, fibrous juvenile roots that assist the radicle function as the seedlings grow, with limited absorption and fixation abilities. This is why we often see that when thick roots appear, they frequently push the seedlings away from the soil surface. Only when relatively thick roots, intermediate between the thick, fleshy roots and juvenile roots, appear, does the growth of Haworthia seedlings begin to accelerate. At this point, supplemented with dilute foliar fertilization, the maximum growth can be achieved.
Haworthia is a monocot, and the 2-3 leaves that grow after the cotyledon are all juvenile leaves, with little expression of varietal traits. If sowing is done by broadcasting and the density is high, many people will adopt transplantation to solve the problem of crowded seedlings.
Several issues should be considered for transplantation:
First is the timing of transplantation. Although Haworthia is not a direct-root type and not suitable for transplantation, early transplantation often delays growth and has a low survival rate. I encountered the problem mentioned earlier, transplanting after only 3 months of sowing, when the first leaf (cotyledon is 0 leaf) had just emerged, and there were only weak radicles. It was difficult to achieve damage-free transplantation, and the efficiency was low. Moreover, the seedlings not only recovered slowly but also had a significant loss, with approximately 5-10% of my seedlings lost. I consider this a relatively high survival rate because I was extremely careful during the transplantation process, trying to achieve damage-free transplantation. Four months later, there was a significant difference in growth between the transplanted seedlings and those that were not transplanted. The non-transplanted seedlings had an entire extra leaf compared to the transplanted ones. Keep in mind that having an extra leaf at this stage is a completely different concept from having an extra leaf in the mature plant. Therefore, transplantation before the 2-leaf stage is not recommended. There is another parameter for transplantation timing, which is the season. Since sowing in autumn, my transplantation season is winter. Although winters in Jiangsu and Zhejiang are not as cold as in the north, they are still the slowest growing season for Haworthia. Of course, I had considered this issue before transplantation and used a heating mat to increase soil temperature, creating a temperature difference between soil and air to promote the germination of new roots and shorten the recovery time. However, reality taught me a lesson. Since the transplanted seedlings were too small, with only one radicle, and the transplantation caused some damage, even though the temperature difference was very suitable for new root formation, the plant was too small and its metabolic level was very low, requiring a long time to accumulate enough energy to produce new roots. Combined with the low temperature of winter, the metabolic level was even lower, so the recovery process of my transplanted seedlings took a full four months. In summary, seedling transplantation should be performed in the spring or autumn growing season after the 2-leaf stage.
Second is the matrix for transplantation. Clearly, a matrix suitable for mature seedlings cannot be used for seedlings about 3 leaves old, and using the same matrix as for sowing will not achieve the desired growth acceleration and avoid the need for another transplantation within a certain period. Therefore, the transplantation matrix should meet the following requirements: first, it should not easily breed pathogens, as transplantation inevitably causes wounds, and a matrix that is prone to or carries bacteria will lower the survival rate of transplanted seedlings. Second, it must have a certain degree of permeability, although it can be slightly lower than that of the mature plant's matrix. Third, the matrix should be uniform, as it can easily lead to uneven growth of seedlings in the same container. Another aspect of uniformity is that the matrix must be easily obtainable, and the physical and chemical properties of matrices from different batches should be basically stable. Only then can we summarize our experience and adapt to the conditions of the matrix to achieve the desired results.
Then comes the preparation of transplantation tools. I use tweezers and a small tray to pull out the seedlings, temporarily store them, and transplant them. A fine mist sprayer is also essential, as it is impossible to complete the watering program after transplantation with a coarse sprayer or watering can. Other items include fungicides or antibacterial agents, mixed in the root-setting water to prevent the invasion of pathogens into the wounds caused by transplantation. Plastic film and rubber bands are used to cover the seedlings after transplantation. I use a combination of rubber bands and packaging wire to solve the problem of sealing, but you can also use other methods to cover if you have a small greenhouse with good humidity, and you can omit the covering step.
The next step is the actual seedling transplantation, which doesn't require much explanation. It involves using tweezers to pull the seedlings out of the sowing container and placing them temporarily in a small tray, then planting them in a new seedling container. However, there are a few issues that need to be highlighted:
1. If you have many seedlings to transplant, you don't need a large tray for temporary storage, or even if it's large, you don't need to place many seedlings in it at once. This is because both the leaves and roots of the seedlings are very delicate and can easily dehydrate when exposed to air. Although you may not see a big difference between the seedlings with the naked eye, the root hairs have already suffered significant damage. Also, try to minimize stacking or not stack the seedlings to avoid minor injuries that can create opportunities for pathogens to invade. To ensure damage-free transplantation, the fewer seedlings the better, but pulling one and planting one is too inefficient. You need to find the right balance, and if you are working in a high-humidity environment (≥90%) with a large enough tray, you can transplant more seedlings at once.
2. During the entire process of transplantation, keep the amplitude of movements as small as possible and handle the seedlings gently, as they are very fragile, and any rigid movements can easily cause damage.
After transplantation, the seedlings should be watered with a sprayer, providing enough root-setting water mixed with fungicides or antibacterial agents. The purpose of the root-setting water is to make the roots of the seedlings adhere closely to the matrix, which is very important for recovery. Also, since the roots or root hairs are damaged after transplantation, the absorption capacity of the seedlings decreases, and the high-humidity environment created by the root-setting water can alleviate the water crisis of the seedlings. After sufficient root-setting water is provided, the whole transplantation process is complete by covering the seedlings. The management after transplantation is the same as that for mature plants, with the seedlings stored in a place with adequate scattered light and suitable temperature for 1-2 weeks before entering normal seedling management.
The comprehensive method explained above for the issues related to the transplantation of Haworthia (Haworthia) seedlings is shared in the hope that it can help solve your problems with green plants.