I am a plant enthusiast; over time, I have realized that yellowing leaves are plants’ cries for help.
Yellow leaves in household plants are a sign of distress, with the causes ranging from nutrition deficiency to under-watering and over-watering.
Causes of and Treatment for Yellowing Leaves in Orchid Plants
Figuring out why my Orchid plants’ leaves turned yellow was a bit of a mystery, but in the end, I did.
When next your leaves begin to turn yellow, consider these simple steps that helped me as your guide to diagnosing your plant.
1. Natural Aging
In several cases, orchid leaves turning yellow is completely natural. When an orchid plant has to develop new leaves, two to three sets of leaves on the lower part of the plant begin to turn yellow and eventually die and fall off the plant.
This happens because orchid plants prioritize new growth and believe that the lower leaves are unnecessary. So it cuts off the water supply to the leaves.
Natural Aging treatment:
Unfortunately, you cannot treat something that happens naturally. You can only continue to water, feed your plant, and get rid of fallen leaves.
2. Moisture Stress
Over-watering and under-watering are the most common causes of yellowing leaves in orchid plants. As these plants are grown in pots, giving just the right amount of water needed for the plant’s growth is very important.
One of the first mistakes beginners make is feeding a plant with too much water. Excess water can be damaging to leaves. If the soil does not drain properly and too much water is left in the soil, causing the root to drown without oxygen, roots begin to die.
You are to water an orchid plant until water begins to trickle from the bottom of its pot. Ensuring that the soil is evenly damp down.
Additionally, when you decide to plant outdoors, do not plant in a location where water pools.
Treatment for over-watering:
To treat over-watering, you have to water your plant less. You also need to ensure that your pot has good drainage. If the water takes unnecessary time to drain out of the pot, you have a drainage issue. We suggest changing pots.
How often your plant needs water depends on how quickly water drains out of the pot. To know when to water, stick a finger in the soil; if it feels dry, it must be watered.
When an orchid plant does not receive enough water, leaves turn yellow and drop to prevent transpiration, to conserve as much water as possible.
An under-watered plant will wilt and droop, and its pot will be light when lifted. Without adequate access to water, your orchid plant cannot absorb essential nutrients from the soil to stay healthy.
Treatment for Under-watering:
When you notice your plant has been underwatered, give the plant a good soak. You can hold the plant under running water, and all the water drains out through drainage holes. Then allow the soil to get dry before watering again.
All plants need sunlight to carry out the process of photosynthesis. However, too much sunlight and too little sunlight can defeat this purpose and cause leaves to turn yellow.
Too much sunlight
In nature, tropical orchids grow in indirect sunlight under thick canopies, where they receive varying degrees of filtered sunlight. They blossom in indirect sunlight and can get sunburned if exposed to direct rays of sunlight.
Sunlight is very important to all plants. However, indirect sunlight is what an orchid plant needs.
Too much sunlight can cause leaves to turn yellow, and if left unattended, the whole plant could get sunburned, causing profound damage.
Change the location of the plant. If your orchid plant is placed too close to the window, reposition it in a place that receives indirect sunlight.
You could also put up sheer curtains between your orchid plant and the light source. This will help strong filter rays of sunlight and provide just enough light to keep your plant healthy.
Too little sunlight
While it is true that orchid plants do not require direct rays of sunlight, orchids are by no means low-light plants. They should not be deprived of sunlight. If your plant this exposed to too little light, your orchid plant will appear limp, with yellowing leaves.
Move your plant from its dim room to a brighter room, so it can receive enough sunlight to produce new growth.
4. Nutrient Deficiency
Orchids are not heavy feeders and so require a consistent amount of nutrients to keep them healthy and thriving. A little drift towards too many nutrients or too few nutrients can cause leaves to turn yellow.
Too much fertilizer
It is very easy to overfeed your orchid plant. Too much fertilizer leads to more nutrients than required in the soil, such as calcium, copper, manganese, etc.
While your plant must have extra nutrients to fall back on in case of a deficiency, the nutrient level could also become too much that it prevents your orchid plant from taking up iron.
This condition is called CHLOROSIS. A sign of iron deficiency is yellowing leaves.
Treatment for excess fertilizer:
Once fed to the plant, it is impossible to take back fertilizer from the soil. However, you can do proper research on how much fertilizer your orchid plant requires.
Another thing to do is not to fertilize your plant in full bloom. You should only apply fertilizer to aid growth when blossoms drop.
Too little fertilizer
Without proper access to nutrients, your orchid leaves will turn yellow. Most orchids lack manganese, iron, zinc, and nitrogen.
To treat nutrient deficiency, apply fertilizer to the soil to boost growth. Ensure that you follow the directions for the application of the fertilizer you purchased.
5. Temperature Stress
Orchid plants are sensitive to temperature changes. After a significant rise or drop in temperature, orchids begin to show signs of distress. You will notice yellowing leaves, leaf drops, as well as browning or blackening of leaves and if left untreated, the plant could die.
Because of such heightened sensitivity, moving your orchid plants from indoors to outdoors is often advised against. Orchid plants thrive in temperatures between 69 – 80 degrees Fahrenheit.
Check that the temperature of the location you’ve chosen for your plant is within the acceptable range. The most efficient way to treat temperature stress is to maintain a consistent environmental temperature.
An infection or a disease can also cause yellow leaves. Here are three common infections and diseases that plague orchid plants.
Fungal leaf spot
When an orchid plant is plagued with this infection, it causes the leaves to turn yellow on the bottom and underside of the leaves. And when left untreated, the spots begin to spread, turning black or brown.
For mild infections, spray or wipe the leaves with a fungicide. You can also get rid of all infected leaves and treat the still-healthy leaves.
Bacterial Brown Spot
Bacterial brown spot plague orchid plants under hot and humid conditions. It is most likely a bacterial brown spot if you notice wet-looking yellow or brown spots on the leaves.
If you leave your plant in this condition untreated, it leads to more yellowing of leaves and, eventually, the death of the plant.
The most effective treatment is to cut out all infected leaves and apply a bacterial spray to prevent the spores from infecting other parts of the plant.
Root rot is a fungal infection of the roots, it occurs when a plant is overwatered or planted in a pot with poor drainage.
Root rot kills plant quickly than any other plant problem. Signs of root rot include; yellowing leaves, brown or black, and fragile and soft roots.
If you notice some still healthy roots you can still save the plant.
Remove all rotten roots with sterile scissors, and replant the orchid in a new pot with a good draining system.
And be careful not to overwater the plant again to prevent another instance.