What causes yellow leaves and scorched tips on orchids?

During their growth and development, orchids often tend to develop yellow leaves or scorched leaf tips, which reduces their ornamental value. There are many causes, mainly the following four aspects.

1. Overwatering or underwatering

Orchids prefer a humid climate, and especially like higher air humidity. If water is insufficient for a long time and the air is too dry, the roots will shrink and their absorption function will weaken, causing water and nutrients to fall short of demand, which in turn causes leaves to turn yellow or tips to scorch. Conversely, watering too much and keeping the potting soil too wet for a long time can easily cause root rot, yellow leaves, and even death.

2. Too much or too little light

When growing orchids, if the placement is inappropriate and the light is too strong or too weak, it can also cause yellow leaves, scorched tips, or withered and scorched leaf margins.

3. Fertilizer applied too concentrated

Orchids are suited to light fertilizer, not concentrated or raw fertilizer. If fertilizer is applied too concentrated at one time, especially excessive chemical fertilizer, it often damages the roots and then causes yellow leaves or scorched tips.

4. Damage from pests and diseases

When orchids are attacked by pests and diseases, it can also damage the leaves and roots of the plants, ultimately leading to yellow leaves and scorched tips. In addition, unsuitable soil pH (soil on the alkaline side), long-term lack of fertilization or failure to repot and change the soil, and environmental pollution can all easily cause orchid leaves to turn yellow, wither and yellow, or have scorched and withered leaf margins and tips.

In response to the above causes, the following preventive measures can be taken:

1. Water scientifically

Whether to water and how much to water should be decided according to the season, the growth and development stage, and the dryness or wetness of the potting soil. Special attention should be paid to increasing air humidity and avoiding potting soil that is too dry or waterlogged for a long time.

2. Fertilize reasonably

Apply thin fertilizer skillfully, and never apply concentrated fertilizer or unfermented liquid fertilizer. On the morning of the second day after fertilizing, water once with clear water to dilute the fertilizer and avoid fertilizer damage.

3. Suitable light

Orchids prefer semi-shade. Apart from allowing somewhat more sunlight in early spring and winter, shade measures should be taken promptly after summer arrives to avoid direct strong light. It is best to grow them under a shade frame or in a sheltered spot by a building.

4. Timely prevention and control of pests and diseases

Prevent diseases and eliminate pests as early as possible, with special attention to controlling anthracnose, black rot, and scale insects.

5. Appropriate soil

Choose slightly acidic, loose, and fertile potting soil, pay attention to repotting and changing the soil at the right time, and regularly apply a ferrous sulfate solution once to keep the potting soil slightly acidic.