Does the Radermachera (China doll) prefer acidic or alkaline soil?

The Radermachera likes a fertile, loose, air- and water-permeable soil environment rich in organic matter, and it also has the characteristics of liking moisture but not tolerating drought, and liking warmth but not tolerating cold, and the Radermachera and the Cinnamomum kotoense share many common characteristics. The Cinnamomum kotoense, however, prefers a slightly acidic soil environment, so what about it?

Practice has shown that potted Radermachera grown in a slightly acidic soil environment often maintains good growth, while when a slightly alkaline potting soil is used, the plant's growth state is less than satisfactory. It can be seen that the Radermachera is a green plant that relatively prefers an acidic soil environment. Therefore, when preparing potting soil for it, we should also consider the soil's pH, taking acidic soil as the baseline.

In fact, the Cinnamomum kotoense can survive in acidic, neutral, and mildly alkaline soil environments, and the pH of the potting soil should preferably be controlled between 4.5-8.5. But when it comes to soil quality, it is recommended to use slightly acidic soil to grow the Radermachera. Moreover, the Radermachera's root system is relatively well developed, making it suitable for growing in deep sandy loam. To make the potting soil show a slightly acidic structure, we can adjust the soil's acidity through various means.

1. Add edible vinegar

Adding an appropriate amount of edible vinegar to the potting soil can increase the soil's acidity, making the potting soil more suitable for the growth of the Cinnamomum kotoense. But the amount of edible vinegar must be well controlled and cannot be too much; it can be diluted with water at a ratio of 1:30, and after mixing evenly, poured into the potting soil.

2. Use rice washing water

Usually, after washing rice to cook, you can collect it, put it into a larger container, seal it for 1-2 days, and then use it to water the potting soil. But when using rice washing water, you also need to control the concentration well; it similarly needs to be diluted with water before being poured into the potting soil. In this way, the purpose of acidifying the soil can be achieved while also not causing harm to the plant.

3. Soak fruit peels in water

To obtain acidic water, we can collect leftover fruit, spoiled fruit, or even fruit peels together and put them into a sealable container. Then add an appropriate amount of water and seal the container mouth well to avoid air leakage, allowing the contents of the container to fully ferment. After about 1-2 weeks, we can pour out the solution inside, dilute it, and use it to water the soil.

Of course, in addition to the above three methods, we can also add a small amount of ferrous sulfate, sulfur powder, etc. when watering the Radermachera, likewise paying attention to controlling the amount. We can also directly use a low-concentration potassium dihydrogen phosphate solution (with the concentration controlled at 0.2%) to water the soil, which can often achieve the purpose of acidifying the soil. In short, there are many ways to keep the soil acidic, so you might as well try more and choose a method that suits you, as long as the acidity is controlled within a reasonable range.