Orchids are one of the most beloved houseplants in the world, but many people worry about how to properly care for them.
They are often called fussy and difficult, and seeing your orchid leaves turning yellow and brown can leave you in a panic.
In reality, orchids are easy to grow if you have the right information – and that’s where this ultimate guide comes in.
If you are asking “Why are my orchid leaves turning yellow?”, then read on!
Reasons Why Are Orchids Leaves Turning Yellow
1. Orchid Leaves are Being Burnt by Sunlight
Although orchids are tropical plants, they don’t like direct sunlight as this can burn the leaves, turning them yellow and causing them to die.
The best placement for an orchid is in a room that gets a lot of natural sunlight, near a south or east-facing window but far enough away that it doesn’t get direct sunshine.
You can also shield your orchid with a fine curtain.Not enough light usually causes dark foliage to develop. You can increase lighting by moving or using a grow light nearby.
2. You are Overwatering Your Orchids
These are tropical plants, so they like a lot of humidity but they don’t like sitting in water.
They are epiphytes and grow in the branches of trees in very little soil, using their roots to hold on to the trees and take in oxygen, so they don’t usually have their roots sitting in pools of rainwater.
An overwatered orchid will develop yellow leaves and black, mushy roots (root rot).
How Often Should You Water an Orchid?
Generally, you should water them once a week or slightly more often if it’s very dry, letting the water drench the pot and run out completely.
Generally, a 6-inch pot will require water every 7 days and a 4-inch pot will require water every 5-6 days. Pick the best watering can that will fit your need.
You can also sit the orchid on a bed of gravel or put the container on a humidity tray to increase humidity without putting the plant at risk.
How To Make a Humidity Tray
How to Fix an Overwatered Orchid
Overwatering an orchid will eventually kill the plant but it’s worth it to try and fix the issue, as many orchids can recover.
First, remove the plant from the container and gently free the roots, cutting away all brown and rotting roots with a sterilized pair of shears.
Then, apply a liquid rooting hormone, following the manufacturer’s instructions. Dispose of the soaked potting medium and repot using dry orchid potting mix.
Lightly dampen the potting mix and plant your orchid gently into the mix. Return it to its normal location and monitor, watering only once a week and ensuring the roots never sit in water.
How to Tell if an Orchid is Underwatered
Underwatering your orchid causes dehydration, an issue that results in limp, wrinkled leaves.
You can check your plants roots to see if you are underwatering, as these will look crisp, brown and brittle rather than silver or green with a plump, firm texture.
If your orchid is underwatered, cut away the dead roots with a pair of sterilized sheers and give it a soaking in fresh water for about an hour, after which you can remove it, letting all the excess water drain out.
Water it once a week without letting it stand in water and it should recover.
Should You Mist Orchids?
Orchids like humidity and this method doesn’t put the roots at risk of rotting, so misting orchids is recommended.
Try misting your plant on a daily basis in between your weekly watering without soaking the roots or leaving the plant in standing water.
3. High and Low Temperatures
High and low temperatures can also be a reason for your orchid leaves turning yellow. Orchids like a moderate temperature, similar to what we find comfortable at home.
Too much heat – especially without enough humidity - can dry your orchid out, so the leaves turn yellow and then die.
If your plant is in a very hot space, rather move it to a cooler spot where it still gets enough indirect sunlight.
Very low temperatures can also stress out this plant, which can cause poor growth and premature dropping of blooms. During cold months, move your orchid away from windows where it gets colder at night (keeping it away from hot air vents too).
What you are aiming for is a consistent, warm temperature with minimal fluctuation.
4. The Orchid is Rotting
Poor ventilation and too much humidity can cause your orchid to rot and the leaves to turn yellow. You can see this because the leaves turn yellow and the roots turn brown and mushy.
As with overwatering, this can kill your orchid – and you can fix this by following the same instructions for fixing an overwatered orchid (See #2).
5. You are Over-fertilizing Your Orchids
Orchids need very little fertilizer compared to other houseplants, so it’s easy to overfertilize them. The motto of fertilizing orchids is to “Feed weakly, weekly”. Here’s how:
- Use a balanced granular or liquid 20-20-20 fertilizer that has no urea
- Dilute it to ¼ of the manufacturer’s recommended strength
- Apply this each week as you do your weekly watering
- If your orchid is very dry, rather drench it in water and then apply the fertilizer to avoid burning the roots.
If you over-fertilize (you can usually see a salty-looking crust on the potting medium), flush it out with lots of fresh water.
6. The Orchid Has a Nitrogen Deficiency
Although these plants are not heavy feeders, they do need nutrients like nitrogen to grow and thrive. A lack of fertilizer can turn cause orchid leaves to turn pale, yellow and die.
The best way to fix this issue is to apply a weak solution of 20-20-20 fertilizer (as this contains nitrogen and other essential elements) as you water your orchids for the week. (See #5).
7. A Pest Infection Will Turn Orchid Leaves Yellow
Common pest infestations that can harm your orchid and cause orchid leaves turning yellow include:
Mealybugs and Scale
Mealybugs and scale are generally immobile pests that grow a hard, cotton-like cottony or waxy cover to protect themselves once they’ve settled on a plant.
They are very damaging to the plant and often leave lots of sticky honeydew that attracts ants, so it’s important to isolate this orchid from your other plants and treat this quickly.
This protective covering makes them difficult to remove, so you should remove any large adults by hand.
Because of their overlapping life cycle, you will need to spray your plant with an all-purpose insecticide and remove adults for at least two weeks before you can get it under control.
Keep this orchid away from any other plants for about a month to make sure the infestation is gone.
Spider mites are hard to see with the naked eye, but often leave fine webs where they’ve been feeding. As they feed on the orchid, the leaves can become pale and cause to yellow and die.
To detect these pests, wipe the leaves of your orchid with a white paper towel. If red-brown streaks are on the paper, you have an infestation. Check all your orchids and houseplants and move any infested plants to a separate.
Apply an all-purpose insecticide as the manufacturer instructs for a 64 day period.
Many thrips species feed on pollen and these tiny insects can sometimes be observed running around on blooms. One infested plant can quickly infect others, so separate your orchid if it appears to have thrips.
Plants with thrips often show poor growth, the flowers die quickly and the leaves become spotted and unhealthy. You will need to apply an all-purpose insecticide regularly for a few weeks in order to get your orchid back to a healthy state.
All-purpose Insecticide Spray Will Treat the Infestation
Regardless of which pest is infecting your orchids, an all-purpose insecticide spray will treat the infestation.
The most important thing to do is monitor for these pests and separate infested plants from healthy plants, treating them for a few weeks or months before you can reintroduce them to your collection.
8. The Orchid Has a Disease
Common diseases that can harm your plant and cause orchid leaves turning yellow include:
Leaf Spots and Blights
Fungal leaf spots and blights are usually caused by poor ventilation, poor lighting and high humidity.
You can spot this issue by looking for brown spots on blooms, rot in the crown (base of the stem turns yellow then brown), and leaves turning yellow and dying in sections.
These are very serious conditions that can kill your orchid. Start by removing damaged leaves treating your orchid with neem oil (Indian Lilac oil).
Mix two tablespoons (1 ounce) of neem oil with one gallon of water, spraying the plant thoroughly and repeating once a week until the infection is gone.
Bacterial Brown Spot
Your orchid can develop a bacterial infection if it gets damaged and lead to orchid leaves turning yellow. This often looks like a discolored black spots or a brown spot with a yellow halo on the leaves of an orchid.
Always use sterile tools when cutting your orchid, and remove all leaves with bacterial brown spot.
The symptoms that your orchid will experience will depend on the type of infection that your orchid is experiencing.
Should You Cut Off Orchid Yellow Leaves?
It is almost always a good idea to cut off orchid leaves turning yellow.
This prevents the spread of a pest or bacterial infection to healthy leaves, and prevents the plant from wasting nutrients on keeping a damaged or dying leave alive.
Always use sterile tools (sterilized in alcohol or with soap and hot water) to cut away any orchid’s yellow leaves.
All the Answers to “Why are My Orchid Leaves Turning Yellow?”
Growing orchids is a very rewarding hobby when you have all the right information on how to avoid overwatering or underwatering your orchid, how to fertilize your orchid properly, how to avoid and treat common pests and diseases, and how to remove yellow leaves and dead roots safely.
After reading this ultimate guide, you now know exactly what could be behind your orchid leaves turning yellow and brown, what to do about it, and how to prevent it from happening in future. Happy growing!