The golden ratio of water quality for cultivating十二卷 (Disocactus) - pH
For many girls, knowledge about cultivating多肉植物 (succulents) such as 十二卷 is important. Let's learn about the golden ratio of water quality for cultivating 十二卷 - pH together.
The golden ratio of water quality for cultivating 十二卷 - pH 5.0
Many friends from the north, Shanghai, and other places may have noticed this issue: the water hardness is too high!
This is manifested by the appearance of salt deposits (white salt spots) on the surface of plants after watering, various types of salt crystals (white dots) on the side surface of the plant's epidermis, and the exudation of various salts on the soil surface, especially when using porous substrates like akadama soil and activated carbon particles as the topsoil layer. Watering from the bottom of the pot can cause a surge of salt, which is siphoned to the surface of the granular soil and crystallizes after drying.
Where do these salts come from? Mainly from several aspects:
1. From the "hardness" in the water, i.e., calcium and magnesium ions, which can form insoluble precipitates with phosphates in the soil or organic acids secreted by plant roots. When calcium and magnesium ions are siphoned to the soil surface or plant's side epidermis, they form carbonate precipitates with CO2 in the air.
2. From the soil, some substrates like volcanic rocks, pumice, and orchid soil may contain some soluble salts or solid calcium and magnesium components during their production. These components can become calcium and magnesium ions in the water through leaching and transformation by plant roots.
3. From fertilizers, almost every enthusiast likes to use foliar fertilizers, mainly composed of potassium dihydrogen phosphate. However, under certain water conditions, this fertilizer can transform into monopotassium phosphate, forming phosphate roots, which combine with calcium and magnesium to form insoluble calcium phosphate and magnesium phosphate.
4. In addition to calcium and magnesium ions forming visible salt crystals, many other salts can also form various chemically inert substances that are insoluble or slightly soluble in water.
What impact do these讨厌 (annoying) salts have on plants?
1. They affect the normal opening of stomata and photosynthesis in plants. Although the respiratory and photosynthetic pathways of succulents are different from most plants, they still have stomata that are widely distributed. CAM (Crassulacean Acid Metabolism) photosynthesis in succulents usually occurs at night when stomata open to release oxygen and absorb CO2 (different from most plants). If salt crystals block the stomata or hinder gas exchange, it severely affects the normal physiology of the plant, leading to growth retardation.
2. They affect the normal absorption of roots. Since the reaction between calcium and magnesium ions and phosphates, carbonates, or organic acids occurs in the liquid of the soil, the formed precipitates are very fine and can completely "clog" the tender root hairs, which are the key sites for absorbing water and nutrients. Many friends wonder why the plants we grow are so different from those in Japan; theirs are fat and green, while ours are dry and thin. Here's the reason: not only is the soil and overall environment different, but the key factor is water quality. Plants in Japan have well-developed root hairs that absorb water quickly and normally, while our root hairs are covered with salt, making watering ineffective, and the root lifespan is short...
3. They affect the osmotic pressure of plant fluids. In addition to the insoluble salts, some slightly soluble salts, such as some sulfates, can also repeatedly cycle between precipitation and solubility in water. These salts can also affect the plant's transpiration, the balance of root hair water absorption, and other links. These links can disrupt the plant's own osmotic pressure balance, leading to abnormal plant conditions, such as changes in window patterns, degeneration of traits, and plant shrinkage.
4. They affect aesthetics, which needs no further explanation...
5. They bring greater trouble to the cultivation process. Due to the presence of these salts, the soil quickly becomes covered with salt crystals, and granular substrates like akadama soil crumble faster, which requires us to change pots more frequently and be more cautious during the summer.
How to remove the influence of these annoying salts?
1. Choose soft water, such as deionized water or purified water. Don't worry about the lack of nutrients in this water, as there are still many nutrients in the soil. Friends who have used soft water for watering plants can deeply experience the rapid improvement in plant condition, including color, fullness, root development, and window patterns, and the salt crystals on the soil surface will also decrease significantly (but it is difficult to eliminate them in the short term, as there are still salts in the soil). The disadvantage of this method is that it is very troublesome and expensive, requiring frequent trips to the supermarket to buy water... The water from home water purifiers also removes some salts but is overall less effective than bottled purified water or distilled water. Moreover, purified water is usually naturally weakly alkaline (pH=7.5-8.0), which is not conducive to plant absorption. Plants prefer slightly acidic water.
2. Use the "closed cultivation" method. People used to have a misconception that closed cultivation grows so well because of high temperature, high humidity, or other factors. These are not the root causes. In fact, closed cultivation creates a cycle of water evaporation and return irrigation. Water is efficiently utilized through daytime transpiration and nighttime condensation, allowing the plant not only to absorb water but also to reduce salts (because the evaporation cycle does not increase the salt content, and water is efficiently utilized), so the plants grown in closed cultivation are robust, primarily due to the efficient use of water, similar to using soft water for watering. However, closed cultivation weakens the plant's resistance, as the plant's resistance is almost non-existent in a non-ventilated environment. Summer or other diseases and pests can cause these plants to die instantly.
Soft water and closed cultivation have their advantages and serious drawbacks. You must be troubled by how to solve the problem properly while minimizing the drawbacks...
Here, I recommend a new method I discovered in recent years - acidified water method: adjust the water pH to around 5.0.
When the water quality is adjusted to the range of 5.0-5.5, the phosphate roots will transform into dihydrogen phosphate roots, and carbonate roots will transform into bicarbonate roots. These anions will no longer combine with calcium and magnesium ions to form precipitates, and the aforementioned drawbacks will be significantly improved. More importantly, this adjustment method is more suitable for the root development of 十二卷, plant growth, and the absorption of water and fertilizers, as the most suitable pH for 十二卷 in plant tissue culture is 5.6, and in soil cultivation, the soil will balance the pH. Therefore, we define the pH of the water for cultivating 十二卷 in potting soil as 5.0-5.5.
Over a period of time, I have privately introduced this method to many friends to avoid salt and alkali, with significant results. Therefore, I call pH=5.0 the golden ratio of water quality for cultivating 十二卷. The main manifestations of plants are fullness, developed roots, no salt deposits, and good trait presentation, with stable plant growth and increased responsiveness to fertilizers and light. Not only is there no longer a need to buy soft water from the supermarket and spend money, but there is also no need for closed cultivation to increase uncertainty.
How to adjust the water quality to 5.0? Currently, the best method after testing is to use hydrochloric acid, as other acids are not as effective, especially avoid solid acids or organic acids.
500ml of concentrated hydrochloric acid costs 6 yuan and can be easily purchased at chemical stores. Boiler rooms, water treatment stations, cleaning rooms, laboratories, and other places usually have hydrochloric acid, so friends can look for it. One bottle can last for several years!
Based on the amount of watering, prepare a week's worth of water in advance in a large bucket, add concentrated hydrochloric acid to adjust the pH, and use pH test paper to measure until the paper is light yellow or slightly red. Taste it with your fingers; if you can't feel the acidity, it's fine (don't worry, our stomach's digestive fluid is also hydrochloric acid, and taking a small amount of dilute hydrochloric acid orally can even treat indigestion). This water can be used for watering or spraying, and results can usually be seen on the same day.
Are there any side effects? I have been using this method for over two years with obvious effects, but it is most suitable for 十二卷 plants and not for terrestrial cacti (especially兜, peonies, which prefer alkaline water).
So far, no significant side effects have been observed, and the plants are growing stronger. However, I think it's possible to alternate between acidified water and normal neutral water after a period of using acidified water. This can prevent the accumulation of too much acidity, and in fact, a pH of 5.0 does not accumulate much acidity, as it is balanced by the plant and soil.
Why not give it a try... I also welcome friends who have benefited from pH 5.0 to share their photos. I will also collect some photos to share with everyone (since I started using it early, it's hard to find early comparative photos now).
The introduction above explains the golden ratio of water quality for cultivating 十二卷 - pH 5.0. I hope it brings a little help to your life!