Variants of the answer to the question, why the orchids turn yellow leaves, can be many. This plant requires due attention and is not always ready to adapt to uncomfortable conditions. The yellowed leaf is not necessarily a cause for concern, but it is better to assess the condition of the plant and understand the causes.
Cause 1: natural yellowing
From time to time get rid of old leaves - this is the norm for orchids. The natural death of a leaf occurs after several years of its life cycle, which differs in different species. It can be a number from 1 to 5 years. Therefore, if an orchid that bothers you has turned yellow only one leaflet, the others are perfectly healthy at the same time, ask how many leaves live normally.
Reason 2: Lighting
Here there can be two scenarios, why the orchid turns yellow. First, lack of light. The trick is that the plant can stand on the same shaded spot for two years and not show signs of discontent, and in the third year begin to turn yellow. In this case, the actions are obvious - to transfer the flower to light. Secondly, the opposite reason is an overabundance of light. Types of orchids, which have a light green color of the leaves, easily burn in the sun. If the surface of the leaves began to feel rough, flabby and yellowed, remove the pot from the direct rays of the sun. Just do not rush to "revive" it by watering, the contrast of temperatures can injure the plant.
Cause 3: Humidity
If the lower leaves turn yellow in an orchid, the cause may be in a constant overabundance of moisture. Roots begin to rot from excess water and cease to cope with their main tasks, which is reflected first on the lower leaves. In addition to changing the color, they can become soft and covered with moisture. If the orchids turn yellow at the base, they become flabby and frown, but the root system has not changed, then we are talking about a lack of moisture. Remember that watering each orchid is individual, one needs water every 2 days, the other does not dry for a week. This is due not only to the type of plant, but also to the conditions of its habitat - the size of the pot, the illumination, the air temperature.
Reason 4: Power
If the orchids have begun to yellow the leaves, but this does not affect their density, they do not dry and are not moistened, then you need to pay attention to the growth of the plant. If it is slowed, then, most likely, the matter is in insufficient recharge. In overfed with orchid fertilizers, too, leaves turn yellow, what to do first of all, is to pay attention to the roots, they can be burned. The only option for salvation is transplantation into a new substrate, with a preliminary soaking of the root system in clean water. After the procedure, the plant is placed in a light and warm place and renews the weak top dressing not earlier than two weeks later.
Cause 5: Diseases
Symptoms of disease most often become yellow spots on the leaves of the orchid. These can be fungal lesions, which are difficult