Orchids leaves turning brown is a serious problem caused by several factors like poor potting medium, light stress, improper watering, pest attack, and disease infections.
The good thing is that you can stop the leaf from discoloration if you know its reason. So now, continue reading to know all about the causes and how to fix them easily.
What Are the Reasons for Orchid Leaves Turning Brown?
The reasons why orchid leaves become brown because of poor soil, unsuitable lighting conditions, and incorrect watering. It would also be because of environmental stresses, nutrient deficiency, and mineral toxicity can also be the reason. Furthermore, pest infestation and disease attacks can also cause brown marks on leaves.
– Poor Potting Medium
The leading reason that causes leaf problems in orchids is bad soil health. It has to be top-notch because the roots depend on it for water and minerals. So, it is understandable why orchid roots cannot perform their role when hostile because note that the potting mix is the plant’s environment in this case.
The effect of such soil is visible in the form of brown patches on leaves. The core reason is that both water and nutrients are critical for successful physiological processes. Since such processes are happening in the leaves, discoloration will first happen there, and you will notice this as a sign.
Poor drainage is the biggest potting medium, the soil, and the problem that causes brown marks on the orchid’s leaves. In this, the excess water does not pass through and stays around the roots, which causes suffocation. As a result, nutrients and moisture uptake slow down, which leads to brown blotches.
Another soil problem worth discussing is unsuitable pH—an orchid plant like the potting medium to be slightly acidic. The roots will feel stressed when low, when the pH is less than 5.0, alkaline, or more than 7.0. That is why you must grow orchids in the best potting soil.
– Exposure To Direct Sunlight
When you notice orchid leaves turning reddish-brown, light is the culprit as the strength of the lighting. There is no denying that sunlight is critical for orchids to stay healthy; however, too much of it can hurt the leaf cells.
When the leaf cells face direct light, most of them start to die. As a result, small brown dots begin to appear, and with time, these dots spread, and the whole brown patch will emerge. Furthermore, high-intensity light also increases the plant’s temperature, which leads to faster evaporation. When this happens, photosynthetic capacity declines, and slowly but surely it will be hard for leaves to stay in their natural colors.
– Lack of Light
Growing orchids in the dark or shade can also turn the leaves brown. Light is important for leaves to do photosynthesis; if it is unavailable, orchids will become short on energy or food. When this happens, the emergence of brown patches is a matter of time, as the plant is giving you signs that the light it needs is not sufficiently coming to it.
– Cold Damages or Stress
If the orchid’s leaves are changing their color to brown, and it’s winter, then chances are they are facing cold stress. In this case, note that orchids don’t like below 50 degrees Fahrenheit and start showing problems when the temperature goes below 40 degrees Fahrenheit. If the issue is within this range or even lower, the stress would be apparent from the change of color.
When the temperature goes low, the water in the orchids freeze up or form crystals. This slows down photosynthesis, and ultimately all the internal processes stop. After some time, you will notice leaves curling and losing their natural colors.
– Adding Lots of Water
Another big reason behind the brown-to-yellow leaves is overwatering. Everyone knows that no plant can survive without water. But this does not mean adding lots of it can bring more benefits. Orchids face more damage from overwatering than even watering not enough, especially when it comes to the case of them turning brown.
Overwatered orchids are prone to deadly fungal diseases like crown rot, which can cause brown marks on leaves, and then it takes on the whole leaf. As a result, you will see that air cannot pass through when more water is near the roots, and this will hurt the roots, and they will eventually stop absorbing water and nutrients. The problem can be aggravated if the soil needs better drainage; therefore, watering your orchids with care is super important.
– Drought Stress or Bone Dry Soil
When you see orchid leaves getting brown in the middle, and the soil is dry, you haven’t added enough water lately. Adding sufficient water to orchids is crucial to keep the internal processes going. Furthermore, it maintains the inner temperature too. So, if you don’t apply it, orchids will face stress.
First, leaves curl inwards to stop the water from leaving the surface area. With time, the photosynthesis process will slow down, which will cause brown to tanned spots to appear, and you will see that the plant no longer has the energy to grow further. If the condition persists, these spots will turn yellow and dark, meaning the leaf is near its dead due to the lack of energy and chlorophyll production.
– Applying Impure Water
People who love gardening must know that orchids are sensitive to water’s impurities, salts, or toxic elements. People unintentionally end up adding hard water with high salts in it, and these salts or minerals build up in the soil, which roots can absorb. They clog the leaves, ultimately forcing them to lose their color and to turn weaker and brown.
This is a course that often happens when you irrigate using tap water to the orchids, and they would face this problem. In most cases, the tap water is clean; however, if you live in inner cities, near any construction site, or industrial zone, the chances of this water getting polluted are more. They would be filled with different minerals and maybe even toxic water, and this is why they would cause such an issue.
To confirm, you can use test strips as well. You may also send a water sample to a state-certified lab to reconfirm. If this is the case that, then to be sure, you may do it this year because your health depends on it.
When you see leaves turning yellow and brown after you apply fertilizers, it means you weren’t careful with the application. Undoubtedly, orchids need nutrients to produce new growth throughout the season; however, excess fertilizers can cause lots of problems.
The biggest one is fertilizer burn, which is a worrying condition in which roots get damaged due to a high dose of nutrients. Furthermore, adding more fertilizers than needed can alter the soil pH.
When the pH changes, the nutrients available in the soil will be “locked.” The roots won’t be able to uptake them no matter how much they try; as a result, nutrient deficiency will occur, which can cause discoloration.
– Lack of Minerals in Soil
Not adding sufficient nutrients is the main reason behind brown or yellow orchids. You have just read how adding more doses of fertilizer is bad. Similarly, adding no minerals/nutrients harms the orchids because nutrients participate in physiological functions.
Nitrogen, magnesium, and iron also make up chlorophyll- a pigment responsible for leaves’ green color. So, when these nutrients are not available, discoloration is unavoidable, and it will be worrying.
First, the leaves turn yellow, which is a beginning sign, and then, they will turn brown and droop down. After some time, the old leaves start to fall off and when they fall you will see how weak they look. If you don’t add fertilizers, the orchid will become fragile and helpless against outside invaders, such as disease pathogens, and will be left vulnerable.
– Unsuitable Humidity Levels
Optimal humidity is important for orchids for smooth growth; for this, they like it to be between 55 and 70 percent. This means that if it is low, then you will see brown tips, and now, the reason is that water evaporates more when the moisture is less in the air.
This keeps happening for hours, and a time will always come when the orchids will have no more water to evaporate. In this situation, you will see the tips of an orchid leaf becoming brown as a sign of stress. Then, all the leaves will start to curl up, which is one of the natural responses of orchids to save the water from leaving.
You should use a humidity gauge to confirm if low humidity causes damage. If it shows below 50 percent, then you know the reason behind the brown patches on leaves.
– Pest Attack
One of the biggest orchid leaf problems is the pest; they suck the juice or the chlorophyll in it and can devour it entirely. You will see the pests around the orchids: aphids, thrips, mealybugs, scale insects, slugs, and snails.
Most of the orchid pests are sucking insects, and they would deteriorate the life of the leaves. What they do is absorb the cell sap or the juice from them that contains chlorophyll. As a result, you will see brown marks on infested leaves, and as the leaf weakens the color fades. Furthermore, they can leave sooty mold on the leaves too, and it is a sticky substance that is black/dark brown.
This sooty mold also causes yellowing leaves. It covers the leaf area and stops the light from reaching there. Due to this, the photosynthesis rate declines, discoloration becomes inevitable, and the plants suffer.
– Disease Infections
Disease attacks can also turn leaves yellow and brown in no time. Both bacterial and fungal diseases invade orchids and can seriously damage them. The common one is root rot, a fungal disease due to overwatering and the roots weaken and no longer have the ability to keep the plant healthy.
In this, the fungus attacks the root, which causes them to rot, you can get an idea about it from the disease’s name. The damage can spread to stems and leaves too. Since the roots start to die, the nutrient and water uptake is hit. As a result, the leaves will start changing their colors to brown.
Leaf spot is another disease that impacts the leaves, but of course, the sizes of the spots vary. You may see a big and small one right next to it, and in a bacterial brown spot, you will see a circle or oval-shaped spot in the middle of a leaf.
So, what causes orchid leaves brown spots? Soggy soil is the main reason behind the attack of diseases. In addition, clean your garden regularly to prevent pathogens from building up and attacking the plants; furthermore, new pots or plants, that are infected are also the bringers of diseases.
– Post Transplanting Stress
The plant faces transplant shock when you notice orchid leaves turning brown and yellow after repotting. It is common for roots to take some time to familiarize themselves with the new potting medium and environment. During this time, they stop absorbing water, which causes leaves to curl.
Furthermore, the nutrient uptake also stops, which can worsen the matter. In short, the orchid will be both water and nutrient deficient, which would be why you see brown patches on the leaves after repotting.
– Leaf Age Is Completed
Sometimes, the discoloration is not anyone’s fault; on the contrary, the leaves may have lived their life, and it’s now time to become brown and fall off. It usually happens in the autumn when the orchids prepare to enter the dormant stage.
So, if the orchid leaves have big brown patches, and it’s autumn, don’t worry, because this process is natural. But if it’s still the growing season, then it is an issue that would occur differently.
How To Fix Brown Leaves on Orchids?
To fix the brown leaves on orchids, you should first improve the condition of the potting medium by adding compost. Then, ensure the orchids receive adequate water, light, and nutrients.
Protection from environmental stresses, pests, and diseases is crucial to maintaining the leaf color.
– Strengthen the Potting Medium
When leaves start to discolor, the first thing you should do is to make the soil great again. For this, you should add compost or sphagnum moss, and now, with these soil amendments, you will see that there is an improvement in the drainage, and it will also add nutrients to the soil.
Furthermore, if you notice the drainage is really poor, remove as much soil as possible and add a well-drained layer. You can aim to add orchid mix or bark chips instead of any soil for this; that is how it will start to establish its proper growth again.
Next, measure the soil pH with strips or a pH meter, and check that if it is below 5.0, it means the environment for the roots is too acidic. To make it more suitable, add lime. If the pH reading is more than 7.5, it means the potting medium is too basic, and now, to make it more favorable for roots, add wood ash or sulfur.
When you do all these things, the root will be the happiest. When they become happy and stress-free, the water and nutrient uptake will take place smoothly, making leaves more shiny and green. You will see that after a bit, the plant will come back to itself, and get rid of the brown color.
– Place the Right Lighting
Of course, you would have to grow some healthy orchids, and this is how you should make sure they receive indirect light for around six hours. For this, choose an ideal area/spot to put the pots.
Indoors, you can put the pots near a window. If you have Grow lights, then it is even better. You can manage the lighting conditions easily with them, but yet again, you should ensure that the light comes indirectly.
However, when it comes to finding the ideal spot for the outdoors is challenging. If there is no such space, we suggest you use a shade cloth to protect your orchids from direct sun rays, especially during the peak sunny hours.
– Add Water the Right Way
You should water orchids properly if you don’t want to see any discoloration on the leaves. You should first check the water quality using test strips, and notice that if it is slightly impure, add distilled water to the orchids instead of tap water.
The timing of watering is critical because you do not want to do it over; as a result, first sense the moisture in the soil using a moisture detector or your hands, if you don’t have the detector. If the soil feels dry, it’s a thumbs up, and you can apply water. On the contrary, if it feels wet, wait a day or two to moisten it again.
The watering method is also important, just as the watering schedule is. If you pour water into the soil, the soil is more likely to become overly moist, and the roots will become vulnerable. The optimal ways of watering orchids are misting and Ice cube methods.
In misting, fill the water in a spray bottle and mist the soil and leaves, or you may also go ahead and out two ice cubes on top of the soil in the ice cube method. The melting ice will moisten up the soil. The chances of overwatering are almost zero when you follow any of these two methods.
– Fertilize With Care
Orchid plants should be fertilized sufficiently, and make sure that you do it very strictly and not overly. It is better to choose those fertilizers that are specifically manufactured for orchids. Apply a dose once a month, and the soil will neither lack nutrients nor become toxic, and this way you will avoid having brown or burnt leaves.
– Provide Protection From Environmental Stresses
If the humidity is low, you should mist the orchids with water daily. You can also put a water-filled tray next to the pot to neutralize the impact of dry surroundings. But the best strategy for dealing with low humidity is using a humidifier.
What you can do is to bring the orchids inside the home to deal with the cold temperatures if you are growing them outside. It is because the temperature inside a home is somewhat warmer. Furthermore, it would help if you turned on the heater too.
– Help Roots Get Out of Repotting Shock
It is really easy to get orchids out of transplant or repotting shock. In most cases, simply adding water regularly works, but remember that if it doesn’t work, give a small dose of fertilizers. In addition, root-boosting hormones can also encourage roots to start growing too.
– Control Pests and Disease Spread
If you see pests on leaves, then immediately apply organic repellents. The best ones are neem oil, baking soda, and diatomaceous earth. If you still see many insects in your garden, use chemical insecticides, and you can spray on them, as these will tackle the pests directly and kill them.
In case of root rot or bacterial infections, the first thing to do is to let the soil become dry. You can also remove the top layer of wet soil and add a dry one. Then, cut yellow and brown parts to stop the spread. When the disease attack gets severe, there is no choice but to apply appropriate fungicides and bactericides.
It is also important to check the drainage holes of pots. If they are clogged, then the water won’t pass through. This will keep the soil moist, which the pathogens love. So, unclog it using your fingers or a stick.
All in all, many things cause orchid leaves to become brown, and we explained them in this article. Here is the list of key points to revise all the important details discussed above:
- Make sure the soil is well-drained, aerated, and nutrient-rich.
- Orchids should receive six hours of indirect light.
- You should never overwater the soil or let it stay bone dry for long if you want leaves to stay healthy.
- Protecting the orchids from environmental stresses, pests, and diseases is important.
You know all the reasons that your beautiful orchid’s leaves have turned brown. On the flip side, you now know so well how to tackle them and have green leaves again.
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