What causes black spots on hydrangeas? How to remedy black spots on hydrangeas?

Hydrangea is also quite common in our daily life. Because of its gorgeous flowers and various colors, many flower lovers will grow them at home. However, many people have encountered the problem of black spots on hydrangeas during cultivation. So what is the problem of black spots on hydrangeas? How to remedy black spots on hydrangeas? Let's take a look.

Why do hydrangeas have black spots?

Hydrangea is a relatively disease-resistant flower, with relatively few diseases and insect pests. However, if hydrangea is planted in an unsuitable environment, it is easy to get some diseases and insect pests. This kind of leaves are full of purple-red spots, and the center of the spots turns brown. It is generally caused by anthracnose, which is a common disease in the hot summer season. It not only occurs in hydrangeas, but also has a great impact on roses. In autumn, it will stop after October.

If it is kept in an unventilated place, a closed balcony, or a room with few windows, it is likely to break out frequently, especially when it is rainy and cloudy, the plants are planted densely and the ventilation is poor.

How to remedy black spots on hydrangea

The solution is relatively simple: do not place potted plants too densely, open windows frequently for ventilation, or place them on the terrace.

Clean up the leaves with diseases and insect pests, don't throw them into the flowerpot, throw them outside. If there are many infected leaves, just prune them and wait for new branches to sprout. It's easy to deal with. Or spray some medicine, such as thiophanate-methyl or methyl thiophanate, to disinfect and sterilize.

Why are the new leaves of hydrangea so small?

1. There may be too much phosphorus and potassium fertilizers and too little nitrogen fertilizers, so when applying fertilizer, pay attention to comprehensiveness and use compound fertilizers containing nitrogen, phosphorus and potassium.

2. If you water too much and get too little sunlight, the hydrangea seedlings will not grow healthily. If you are growing hydrangeas in pots on an indoor balcony, the temperature is gradually getting cooler now, so you don't need to water them too much in one day. Too much water will easily suffocate the roots and cause them to become dry and wet.

3. Do not fertilize too frequently or too much at one time. The seedlings are still small and it is difficult for them to bear such fertilization.