How to Grow Madagascar Periwinkle? Yellow Leaves Can Be Solved This Way

Madagascar periwinkle, also known as riri-you, riri-chun, and shanfan flower, is a perennial herbaceous or semi-shrub plant of the genus Catharanthus in the Apocynaceae family, native to various parts of tropical Africa, and has been cultivated throughout our country. The Madagascar periwinkle has a long flowering period, is mostly grown in pots for ornamental display, and can also be used as summer and autumn flowerbed and flower border material, or is suitable for planting in parks and home courtyards to beautify the environment. So how do you grow Madagascar periwinkle? What should you do when leaves turn yellow?

I. How do you grow Madagascar periwinkle?

1. Sunlight

Madagascar periwinkle is a light-loving plant. During the growing period it must have sufficient sunlight, so that the leaves are dark green and glossy and the flowers are brightly colored. If it grows in a shady place for a long time, the leaves turn yellow and fall off.

2. Soil

Fertile and well-drained soil is suitable. It tolerates poor soil, but must absolutely not be on the alkaline side. In compacted, poorly aerated clay soil, the result is poor plant growth, yellowing leaves, and no flowering.

3. Temperature

It likes a warm, slightly dry, and sunny environment. The suitable growing temperature is 18~24°C from March to July, and 13~18°C from September to March of the following year. In winter the temperature should not be lower than 10°C.

4. Watering

Madagascar periwinkle dislikes moisture and fears waterlogging, so the potting soil should not be watered too much; excessive moisture affects growth and development. Especially for plants overwintering indoors, watering should be strictly controlled, and it is better to keep them dry, otherwise they are very prone to freezing damage. For open-ground cultivation, during midsummer rain showers, pay attention to timely drainage to avoid waterlogging that causes the entire patch to die.

5. Fertilizing

When fertilizing, you can adopt a method of alternately applying compound fertilizer and liquid fertilizer once every ten days. A layer of base fertilizer should also be spread at the bottom of the Madagascar periwinkle pot as much as possible to ensure the nutrient content of the potting soil.

6. Pests and diseases

Pests: The Madagascar periwinkle plant itself is toxic, so it is relatively resistant to pests and diseases. The main diseases at the seedling stage include: seedling damping-off, gray mold, etc. In addition, prevent the occurrence of fertilizer damage and pesticide damage at the seedling stage. If they occur, immediately water thoroughly with clean water, strengthen ventilation, and reduce the harm.Diseases: Madagascar periwinkle stem and leaf rot mainly occurs in the rainy season, and its pathogen is Phytophthora. When the disease is severe, it causes a large number of deaths and seriously affects mass production. Chemical control method: before rain, protect with 65% Hao Sheng Ling at 600~800 times or 1% equal-amount Bordeaux mixture. If the disease occurs, promptly spray 72% Kelu at 600~800 times or 25% Puli Ke at 600~800 times, spraying once a week for a relatively good control effect

8. Pruning

Madagascar periwinkle is an herbaceous plant and is relatively suitable for pot cultivation, but care should be taken not to let the plant grow too tall, which would affect indoor decoration and ornamental value. Therefore, after it survives in the pot, pinch the tips several times to promote more branching and more flowering. After flowering, the spent flowers must be cut off.

II. What should you do when Madagascar periwinkle leaves turn yellow?

1. Poor soil aeration

Poor soil aeration is also a cause of Madagascar periwinkle leaves turning yellow. The soil many people use for planting flowers is relatively 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 the Madagascar periwinkle, leading to frequent yellowing and falling of leaves.

Solution: Choose sandy soil with good drainage performance for planting, and also be careful not to water too much.

2. Overwatering

Madagascar periwinkle dislikes moisture 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 be tender yellow.

Solution: Strictly control watering, and it is better to keep it dry. During the rainy season, pay attention to drainage.

3. Overfertilizing

Many flower enthusiasts worry that the Madagascar periwinkle does not have enough nutrients and will not flower well, so occasionally they put a little fertilizer or something into the potting soil, hoping it will absorb more and bloom more. This method is correct, but the mistake lies in the frequency of fertilizing. If fertilizer is applied frequently, it is very difficult for the Madagascar periwinkle to absorb it completely. The fertilizer remains in the soil, always surrounding the roots, causing the entire Madagascar periwinkle plant to become listless, grow slowly, bloom less, and have smaller petals.

Solution: Madagascar periwinkle can adopt a method of alternately applying compound fertilizer and liquid fertilizer, and at other times do not fertilize casually. Water the day after fertilizing to promote nutrient absorption.