Orchids are visually appealing and a popular house plant because they are easy to maintain. They can also survive in various conditions. Unfortunately, if something goes wrong, orchids will communicate with yellowing leaves.
An orchid’s leaves turning yellow can be due to the roots’ inability to move nutrients and water around the plant. This often results from overwatering or underwatering. Temperatures below 55°F (13°C) can also cause orchid leaves to yellow. Notably, yellow foliage paves the way for new leaves.
If your orchid’s leaves are starting to yellow, keep reading. I’ll share all the reasons why this is happening and provide you with solutions to get your orchid back to full health.
Why Your Orchid’s Leaves are Turning Yellow
There are multiple reasons behind your orchid’s sudden change in leaf color, from dark green to yellow. Here, we’ll discuss 11 possible causes for yellowing leaves and how to restore your orchid–-or, at least, prevent it from dying.
The leading cause of yellowing in orchid leaves is overwatering. When the orchid is flooded with water, the roots struggle to absorb water and nutrients from the soil. Without food, the leaves lose their elasticity and turn yellow.
Overwatering also causes the root system to become weak. Eventually, your orchid may reach a point of no return, and the root system won’t be healthy enough to support the health of the entire plant.
How To Fix It
Check the soil to find out if it’s wet or dry. If it’s slightly wet, avoid watering again until the soil dries out. And if the soil is soaked, it’s best to repot the orchid in fresh soil.
If you leave the orchid in soaked soil, the chances for root rot are high. Be sure to check for signs of rot before repotting. Healthy orchid roots are plump, stiff, and green. If the root is mushy or has an unusual dark color, the root is damaged.
Should root rot be present, you must get rid of the dead weight. Cut off the rotten roots and sterilize the rest with hydrogen peroxide 3%. You can now plant the orchid in another pot with fresh soil. Just be sure to avoid overwatering it. In general, it’s best to water your orchid once every 7-14 days.
This video illustrates how you can cut off the affected roots instead of throwing away your orchid:
2. The Soil Doesn’t Drain Well
Initially, an orchid requires more frequent watering because the bark dries out quickly. After a few weeks, the bark becomes more absorbent, and watering can be reduced. However, the soil may still retain too much water–not necessarily because you are overwatering it–which can cause the orchid’s leaves to turn yellow.
How To Fix It
Instead of using potting soil or moss, use bark clippings as the planting medium. Whether it’s Fir, Pine, or Douglas bark, such clippings don’t retain moisture and prevent adequate air circulation around the roots.
The Sun Bulb Better Gro Special Orchid Mix on Amazon is an excellent medium for growing your orchid. The pack has a combination of fir bark, sponge rock, and hardwood charcoal. It offers superior drainage to protect your orchid roots from rot.
3. The Pot May Be Without Drainage Holes
Another possible reason for a sudden change from green to yellow in your orchid’s leaves may be due to a lack of drainage holes in the pot.
Most of the decorative pots in the market are made of ceramic and don‘t have drainage holes at the base. Even if you have a pot with drainage holes sitting in the decorative outer pot, the water won’t escape as quickly as if using a tray.
How To Fix It
While the appeal of an orchid plant is enhanced when plante in decorative outer pots, a tray is the better option. This way, you don’t need to worry about the roots sitting in moisture for too long.
Ensure the pot you use for your orchid has drainage holes at the base. Use a tray to hold the escaping water and ultimately bottom feed the orchid from the base.
If an orchid isn’t getting sufficient water, the leaves turn yellow. This is mainly attributed to dying roots that can’t support the movement of water and nutrients to the leaves. Besides yellowing leaves, under watered orchids can be identified by roots shriveling and turning white.
How To Fix It
There are several ways to help a dehydrated orchid:
- Use the soaking method. Place the orchid pot in a sink filled with water to rehydrate your orchid quickly. Leave the pot to soak in the water for 20-30 minutes. Lift the pot from the sink and shake off any excess water. Monitor the potting medium henceforth for signs of drying, and water immediately once it’s needed.
- Rinse the roots in lukewarm water. Remove your orchid from the pot and cut off badly damaged roots. Place the orchid in a water container, ensuring only half of the roots are immersed. Occasionally change the water, and leave it for a week or two. Don’t allow it to sit any longer or it may rot again. Repot the orchid when it has recovered.
- Place 3-4 ice cubes on the potting medium. This is a slow-recovery method, but it eliminates any risk of overwatering the orchid. If preferred, this method can become your regular watering routine.
- Use an orchid humidity box. If humidity is low in your home, an orchid might be losing most of its water to the environment. Even if you properly maintain a watering schedule, drying out occurs faster because it’s losing water to the air. Placing the orchid in a clear humidity box helps to retain water longer and rehydrate it faster.
5. Exposure to High or Low Temperatures
Orchids are sensitive to temperatures higher than 80°F (27°C) and lower than 55°F (13°C). When exposed to unusually high or low temperatures, the orchid will start showing signs of stress, including yellowing leaves. If left unchecked, orchid leaves will turn brown and even start to drop. Ultimately, your orchid will die from temperature stress.
How To Fix It
Occasionally check the temperature of the room or area your orchid is located. Avoid placing it near a window that gets hours of direct sunshine, as the window temperature fluctuates both in summer and winter. Instead, place your orchid in a moderately warm area away from direct sunlight.
6. Use of the Wrong Fertilizer
While regular plant fertilizer sometimes works on orchids, it can sometimes burn them and cause the leaves to turn yellow. Orchids tend to be fussy and may react negatively to being fed the “wrong” fertilizer meant for other plants.
How To Fix It
Use orchid fertilizer once a week to boost your orchid’s growth and health. General plant fertilizers tend to have the same components, primarily:
- Magnesium sulfate
- Calcium nitrate
- Cobalt sulfate
- Potassium nitrate
- and many more
However, the composition of the orchid fertilizer is specific to the feeding needs of the orchid plant. It’s specially made to ensure orchids get all the necessary nutrients in small portions. Orchids require fertilization once a week.
Miracle Gro Orchid Food (available on Amazon.com) is a solid orchid fertilizer made to ensure your orchid has deep green leaves, a strong root system, and beautiful blooms.
7. Change of Environment Shock
If you recently repotted your orchid, the yellow leaves may result from transplant shock. Orchids tend to react to sudden changes in the environment. It could be the movement from the store to your home or a change from one pot to another. Your orchid may even react to you moving houses.
When stressed, the orchid’s leaves will turn yellow. Sometimes, the orchid will start dropping its leaves flowers.
How To Fix It
If the change of environment was inevitable, a healthy orchid is likely to bounce, so you could wait it out until the orchid adjusts. Avoid further stress by placing it in the wrong location; place it away from direct sunlight and maintain the right room temperature.
Orchids prefer small to medium pots, usually 4 – 6 inches (10 – 15 cm). Larger orchids may require larger pots. Take care to avoid getting a pot that’s significantly larger when repotting. Rather, choose a pot that’s an inch (2.5 cm) bigger than the current pot.
The tangled roots of the orchids should fit snugly in the pot. If there’s a lot of space, the pot is too big.
If you use a pot that’s too big, the moisture retention will be higher, which causes orchid leaves to turn yellow.
8. Nutrient Deficiency
Orchid plants start showing signs of stress when underfed. Stalled leaf growth, yellow leaves, and a lack of flowers are some of the signs your orchid isn’t getting the nutrients it needs.
How To Fix
Orchids don’t need much fertilizer. If it’s your first time using orchid fertilizer, it’s recommended to use half of the suggested quantity and then observe your orchid. Should you add too much magnesium and nitrogen, the orchid will struggle to absorb iron. The result will be yellowing from the middle of the leaf outward.
9. Using Chlorinated Water
Orchids are sensitive to the type of water you use. Hard water or excessively chlorinated water is difficult for the orchid to absorb and break down. This water also affects the orchid’s ability to absorb micronutrients, resulting in nutrient deficiency and yellowing leaves.
How To Fix It
If possible, ask to have your water inspected to determine if it’s over-chlorinated. If you find it difficult to get to the root cause, consider installing a filtering system to clean your tap water, or opt for alternative water sources. Alternatives include rainwater or filtered water.
Plant diseases may also be responsible for the yellow leaves on your orchid. And if the leaves have yellow spots or patches, it’s most likely due to a disease.
Some of the common diseases that attack orchids include:
- Fungal leaf spot. The leaves affected with fungal leaf spots usually start yellowing from the underside before progressing to other areas. When left untreated, the spots become bigger and eventually turn brown and then black.
- Bacterial brown spots. Orchids with this disease have wet-looking yellow and brown spots on leaves. This disease mainly attacks orchids placed in hot and humid areas. As the disease progresses, the entire leaf will turn yellow. Over time, all the leaves on the orchid will start turning yellow.
How To Fix
Luckily, the fixes to these particular diseases are easily addressed as follows:
- Fungal leaf spot: Remove infected leaves and treat the remaining leaves with fungicide. The leaves that appear normal may not be showing signs of infection, yet they may be affected.
- Bacterial brown spots: Cut off the infected leaves, then use a bacterial spray or fungicide to prevent further plant damage.
11. Natural Part of the Orchid’s Life Cycle
Plants shed off leaves as they go through the natural phase of their lifecycle. As the orchid plant gets new leaves or a new flower emerges, the lower leaves start turning yellow before they dry and fall off.
Orchids usually prioritize new growth, so they shed old leaves to preserve nutrients. They do this by depriving the leaves of water, intentionally dehydrating them, which then start turning yellow.
How To Tell
You can distinguish if the yellowing is part of the orchid’s normal process when it’s the lower leaves turning yellow. If the problem doesn’t affect the rest of the leaves, you have nothing to worry about.
It’s best to wait for these leaves to dry and fall off on their own. Don’t attempt to remove them, as that could create an open wound that’ll be susceptible to infections. Instead, you can cut off the leaves with a sharp knife, but only when they’re dry and weathered.
There are several possibilities behind your orchid’s leaves turning yellow. Consider the most probable reason and continue eliminating causes until you find the culprit. It sometimes takes orchids a bit of time to recover, but these solutions can help keep your orchid from dying.