Reasons for Yellowing Leaves on Catharanthus roseus and Solutions

At first glance, everyone will surely associate Catharanthus roseus with Changchun City in our country, but in fact this flower has nothing to do with Changchun City. In China, Catharanthus roseus is mainly cultivated in areas south of the Yangtze River, and it has not been cultivated in China for a very long time. Because this flower has a very long flowering period and can bloom almost all year round when grown properly, it is a relatively common flower in our lives. However, during cultivation we often find that this flower develops yellow leaves. What should we do then? Below, Qinnong Web will introduce the reasons that cause the leaves of this flower to turn yellow, as well as the solutions after the leaves turn yellow.

1. Soil on the alkaline side

Catharanthus roseus can grow well in ordinary soil, except for saline-alkaline land. Catharanthus roseus is not strict about soil requirements, and soil that is well ventilated, fertile and has good drainage is suitable. If the soil is on the alkaline side, it will cause poor growth of Catharanthus roseus, leading to yellow leaves and no flowering.

Solution:

Before planting, test the pH of the soil to be used. If the soil is on the alkaline side, it must be treated. You can buy acidic soil directly at a flower shop, or add ferrous sulfate solution to the soil, which can both acidify the soil and increase its fertility.

2. Poor soil air permeability

Poor soil air permeability is also a cause of yellowing leaves in Catharanthus roseus. The soil many people use for planting flowers is fairly sticky and has poor water permeability. This kind of soil may not show any problems in the short term, but over time, soil with poor water and air permeability causes poor respiration of the lower roots of Catharanthus roseus, leading to frequent yellow leaves and leaf drop.

Solution:

There must be some care in choosing the soil. As introduced above, soil that is well ventilated, fertile and has good drainage is suitable. When planting, choose sandy soil with good drainage, and also be careful not to water too much.

3. Overwatering

Catharanthus roseus avoids wet conditions and fears waterlogging, so the potting soil should not be watered too much, otherwise it will affect root respiration and cause old leaves to turn yellow and new leaves to turn pale yellow.

Solution:

Catharanthus roseus originates from tropical regions. During cultivation, watering must be strictly controlled, and it is better to keep it on the dry side. Pay attention to drainage during the rainy season.

4. Too little watering

Overwatering is not acceptable, so can you water less? The answer is also no! If you water too little or the water does not penetrate thoroughly for a long time, the plant cannot absorb enough water, new leaves will wilt, and old leaves will turn yellow and fall off.

Solution: During cultivation, pay attention to observing the plant's growth after watering, and find the most suitable amount of water for growth. When watering, implement the principle of “do not water if not dry, and water thoroughly when watering.”

5. Overfertilizing

Many beginners always worry when growing flowers that the flowers will not get enough nutrients, so they often fertilize them. In fact, fertilizing can indeed make flowers bloom more and more beautifully, but if it is too frequent, it will have the opposite effect. If fertilizer is applied frequently, it is very difficult for Catharanthus roseus to absorb it completely. The fertilizer remains in the soil, always surrounding the roots, causing the whole Catharanthus roseus plant to become listless, grow slowly, bloom less, and have smaller petals.

Solution:

For Catharanthus roseus, you can adopt a method of alternating the application of compound fertilizer and liquid fertilizer, and do not fertilize casually at other times. Water the next day after fertilizing to promote nutrient absorption.

The above are the solutions introduced by Qinnong Web for yellowing leaves of Catharanthus roseus. Qinnong Web would also like to remind everyone here that the whole plant of Catharanthus roseus is toxic, but after extraction, Catharanthus roseus is also a cancer treatment agent. Therefore, whether you grow it yourself or see it by the roadside, do not eat it casually.