What is the reason for the yellowing of leaves?
The editor introduces the planting content of green plants and flowers for roses after heavy rain in the summer, and next, our site editor will introduce to everyone.
Why do the leaves of roses turn yellow after heavy rain in the summer?
This year's rainfall is particularly abundant, and most of the roses planted outdoors are in the stage of rapid growth. However, many rose enthusiasts have found that their roses are slowly turning yellow and withering, with black leaves and falling leaves. What is the reason for this?
First, the issue of waterlogging
Whether it's potted roses or ground-planted roses, they are particularly afraid of waterlogging. During the summer plum rain season or long periods of consecutive rainy weather, be sure to remember to drain the roses. For potted roses, check to ensure the drainage holes are not blocked or place them in a place where they won't get rained on. If often rained on, promptly pour out the water in the saucer to avoid waterlogging, as积水 can cause damage to the rose roots. After high temperatures, the roots will gradually rot, and the leaves will gradually turn yellow, with black stems withering.
If it's ground-planted roses, attention should be paid to timely drainage. Remove the water around the rose roots. If the soil has too much moisture, roses are also prone to root rot and damage.
Second, underground pests and diseases
In the summer, it often rains, and apart from waterlogging, there are some underground pests that can cause significant damage. They damage the roots of roses, causing yellowing and falling leaves, and even death. The main pests are earthworms and the larvae of longicorn beetles, which are harmful to the roots of roses. They mostly occur during the rainy season in the summer and are fatal to roses. They are not easily noticed at first, and by the time they are detected, it's often too late.
Therefore, in the beginning of summer, it's important to frequently check your roses. If you find longicorn beetles or chafer beetles, eliminate them promptly. They are likely to lay eggs in the soil, and their larvae will damage the roots of the roses. When we notice that the branches of roses are growing slowly or are yellow and soft, we should check to see if there are any obvious signs of root damage or black rot. If the branches look normal on the outside but the leaves are yellow and soft, consider whether it's due to waterlogging or underground pests and diseases.
If you find that the leaves of the whole rose plant are soft and collectively yellow, with only a few weak branches growing, this indicates that there are pests damaging the roots of the roses. The best method is to dig up the roots to find the pests. However, it's not suitable to dig up roses in the summer. We can use insecticides to treat the roots, such as dichlorvos, to ensure that the pests in the soil are killed, and then take good care of them. Roses may grow new roots and come back to life, but if it's too severe, there's no saving them.
Of course, in addition to these pests and diseases, it's also necessary to spray fungicides like carbendazim or mancozeb before it rains to prevent infections like black rot or powdery mildew. It's really difficult to care for roses in the rainy season of summer.
The above are some small experiences with green plants and flowers for roses turning yellow after heavy rain in the summer, hoping it can help you in your daily life!