Cacti Seedling, Grafting, Planting and the Selection of Rootstock
Introduction to this article: Knowledge about the cacti, including the selection of seedling, grafting, planting, and rootstock. Let's learn about them together.
The relationship between seedlings and grafting is very complex. It not only greatly affects the appearance of cacti but also significantly changes the lifespan of the plant. Although seedlings are much more expensive than grafted plants, we should not undervalue grafted cacti. In fact, it is because of grafting that the appreciation and propagation of cacti can be more diversified. Personally, I believe that those who can truly be called "Great Sages" should at least have some knowledge about grafting, and I also advocate that everyone should try to understand it.
Before talking about grafting, we need to understand: universal rootstock, affinity, and perfect grafting.
(1) Why is Longshen called the universal rootstock: First, Longshen has very good affinity, almost compatible with all cactus species. Second, Longshen has a moderate growth rate, which provides a perfect proportion of nutrients to the scion, allowing the scion to closely resemble the seedling. Third, Longshen is one of the few rootstocks with the ability to horizontally proliferate cells at the joint, which greatly reduces the formation of tumor-like tissue at the joint caused by cell misalignment due to grafting (similar to the formation of tumor-like tissue around human wounds), and is less likely to cause blockage, thus being called a permanent rootstock.
(2) Grafting affinity is influenced by the genetic characteristics, physiological functions, biochemical reactions, and internal tissue structure similarities and mutual adaptability of the rootstock and scion. The closer the blood relationship, the higher the moisture/nutrient concentration, the better the affinity, and the higher the success rate of grafting. The quality of grafting affinity directly affects the survival rate, growth potential, resistance, lifespan, yield, and quality of the grafted plants.
(3) Perfect grafting, as the name implies, means that the joint between the scion and the rootstock perfectly aligns, with perfect affinity, and the cells of both perfectly integrate into each other, forming a state where each contains a part of the other. A representative feature of perfect grafting is that the joint thickens as the rootstock grows, forming a permanent rootstock state (which does not mean it will not age), and the grafting site shows the characteristics of both the scion and the rootstock, with no visible incision surface.
The quality of grafting affinity can help us clearly see the closeness of the blood relationship. I once used Jinjialong to graft on Dou, and all survived, but they did not grow at all, which was caused by poor affinity due to too distant blood relationships. When used to graft on Lüekou, the growth rate was very fast. Shebianzhu grafted with Yin grows slowly, but when grafted with Lüekou, it grows very fast. However, after switching to Longshen rootstock, the situation reversed. To avoid these issues, many merchants use double grafting to mitigate incompatibility problems.
Grafting withXiupu or草球, where a large amount of amino acids and sugars from the rootstock enter the scion, can significantly improve the cold resistance of the scion, making it no longer a problem to survive the winter outdoors in the south. When using triangle to graft, the cold-resistant substances in the scion will flow back into the triangle, improving its frost resistance but reducing the frost resistance of the scion, so even if the triangle is cut open immediately after freezing to death in winter, many scions still cannot withstand the low temperature.
These characteristics help us choose rootstocks that are more suitable for our own environment, rather than having a uniform triangle as is common in China. In Europe, the Cereus species is a very popular rootstock. I have seen many Feiniao, Yuezhutongzi, Baihongshan, and the newly discovered Beishi Runtu all grafted with Cereus, because Cereus has a very good tolerance for low temperatures and also has strong anti-rot capabilities. For these difficult-to-grow species, Europeans seem to think that Cereus is more suitable than the universal Longshen for these "rotten kings."
In the selection of rootstock, if conditions permit, it is best to use seedlings as rootstock. If grafting fails repeatedly, please change the rootstock. The mutual penetration of cells caused by multiple grafting will continuously affect the affinity between the next scion and the rootstock, which means there is a potential rejection reaction. Of course, in places like Dahu, where the environment is very suitable, these issues are not a problem and the impact is minimal. But in cities on both sides of the Yangtze River, joint blockage and rejection reactions will be significantly stronger.
Normally, cacti in a perfect grafting state do not need to be planted on the ground, as they have a wooden core and are severely aged.
The introduction above about the selection of cacti seedlings, grafting, planting, and rootstock is hoped to bring some knowledge of flowers to flower enthusiasts.