What to do about the latest curled and rolling leaves on periwinkle?
Periwinkle (Catharanthus roseus) is quite ornamental because it stays green all year round, blooms profusely and has a long flowering period, and it is especially ornamental when grown as a potted plant. As long as you care for and manage it attentively, it generally blooms from spring all the way to autumn, which is why periwinkle has also earned the lovely name "daily spring." Moreover, periwinkle has quite a few varieties and adapts very well to the environment, so with just a little care it can easily be grown into a full pot. However, sometimes factors such as inadequate management can cause periwinkle to develop curled and rolling leaves. What is going on here?
Periwinkle has the characteristic of liking a hot and humid growing environment, and it also has a certain tolerance for shade, but it is not cold-hardy; its optimal growing temperature is 20°C-33°C. Although it tolerates partial shade, it also likes light; although it likes moisture, it is also afraid of waterlogging. So in our daily management we should care for it according to its growth habits, otherwise the leaves of potted periwinkle may develop undesirable growth such as curling and rolling, which will certainly seriously reduce its ornamental value.
Practice has shown that the curling and rolling of periwinkle leaves are often caused by the following factors.
1. Leaves curling upward
If during care and management periwinkle leaves curl upward and take on a cup shape, it is often caused by excessive light or too much water loss. This situation mostly occurs in summer; although periwinkle quite likes hot, high-temperature weather, if it is exposed to the scorching sun for too long in midsummer, the overly strong light will cause the plant to lose too much water, so the leaves curl upward.
If it is due to overly strong summer light, necessary shading measures should be taken in time, and the pot can be moved under the shade of a large tree; and if the potting soil is too dry, it should be watered in time to maintain the moisture the plant needs for growth. But in hot, high-temperature summer weather, it is recommended to avoid watering during the high-temperature period of the day and instead water in the morning and evening. At the same time, you can also spray water more often to cool things down and keep moisture in.
2. Leaves curling downward
If you find that the leaves of potted periwinkle curl downward and take on a cup shape, it is mostly caused by the temperature being too low in the plant's current growing environment. After all, periwinkle is a plant with poor cold tolerance; when the temperature is too low, the plant enters a self-protective state, and this is often shown by curling its leaves.
The most suitable growing temperature for periwinkle is between 20°C-33°C, and it quite likes light, especially in winter; to keep the plant growing well, it needs plenty of light on sunny days. But in winter, keeping warm and protecting against the cold is often more important, and in particular you need to control water in time, otherwise the plant will easily suffer cold damage in winter. After all, periwinkle quite likes warmth, so even in winter the temperature should not be allowed to drop below 10°C, otherwise the plant may suffer cold damage and develop downward-curling leaves and various other signs of poor growth.
In response to this situation, we need to promptly move the pot indoors for care, while taking good measures to keep it warm and protect it from the cold, adjusting the indoor temperature to above 10°C, so as to ensure the plant will not suffer frost damage and to provide protection for it to overwinter safely and smoothly.