What happens if there are black spots on orchid leaves?

Orchids are known for their elegance, beautiful and noble flower shapes, and refreshing fragrance, and are therefore loved by many flower lovers. However, many people find that black spots always appear on the leaves of orchids for unknown reasons, which affects the appearance of the plants. So what exactly is going on? Let’s learn more about it below.

1. Disease infection

Black spots on orchid leaves may be due to certain fungal or bacterial diseases, the most common of which is anthracnose . If not treated in time, these spots will expand and even spread to the entire leaf or other parts, seriously affecting the growth and flowering of orchids.

Solution: After orchids are infected with anthrax, they can be treated by spraying with drugs such as thiophanate-methyl and mancozeb. If some leaves on the plant are infected, they need to be removed and destroyed in time to prevent further infection of other healthy parts. If they are grown in multiple pots, the diseased plants need to be isolated in time.

2. Insect bites

Black spots on orchid leaves may also be caused by insect bites, especially red spider mites, because this pest is small and not easy to be found. Usually in the early stage, the leaves mainly appear as irregular translucent dots, but as time goes by, the translucent dots on the leaves bitten by pests will slowly turn into black spots until the entire leaf is covered with dense black spots.

Solution: It is best to choose the nymph and adult stage after the eggs hatch for prevention and control. You can spray with 20% cypermethrin wettable powder or 1500-2500 times diluted 20% cypermethrin emulsifiable concentrate, once every 5-7 days, for 2-3 times in a row.

3. Other reasons

One is the ventilation problem. If it is kept in a poorly ventilated environment for a long time, it is easy for the leaves and flowers to develop black rot. At this time, you need to move it to a better ventilated environment immediately.

The second is the problem of planting materials, such as improper soil preparation and poor air permeability, which makes it impossible for orchid roots to breathe normally, thus causing black spot problems. Note that when planting orchids, you must use loose and fertile soil with good air permeability and drainage.

The third is the problem of light. Orchids like light but are afraid of excessive exposure to the sun. If exposed to the sun for a long time, its leaves will burn and develop black spots. During daily maintenance, be careful to avoid direct sunlight to prevent the leaves from being burned.

Generally speaking, the above three reasons are the main reasons for black spots on orchid leaves. Moreover, once black spots appear on orchids, they are irreversible, so it is best to take preventive measures before they occur, and generally just do daily maintenance.