Your orchids stem turning yellow can be worrying. It certainly doesn’t look healthy! And isn’t a good sign.
There are a fair few reasons an orchid stem can start to turn yellow. Thankfully very few of them are likely to kill your orchid. And if you changed things up a bit there’s a good chance you can bring your orchid back to health.
So let’s take a look at the most common reasons behind this issue and how to solve what’s behind it.
1. Natural Aging Process
Just like all living things orchids have a natural aging process. As they age the stems and leaves can turn yellow before falling off entirely.
This may not look very nice but it’s a normal part of the plant’s life cycle and doesn’t necessarily mean your orchid has a problem.
Recognizing Natural Aging
- Location of Yellowing: Usually it’s then older leaves at the base of the plant that will start turning yellow first.
- Timing: Doesn’t happen quickly, the leaves will gradually turn yellow.
- Overall Plant Health: The rest of the plant remains healthy and continues to produce new growth.
2. Overwatering
If you water your orchid too much then that can cause the stem to turn yellow. If there’s too much moisture in the soil it can cause the roots to rot and this can affect the health of the stem.
Signs of Overwatering
- Mushy Roots: Healthy orchid roots will be firm and white or green. If they are brown and mushy it’s definitely a sign of rot.
- Yellowing Leaves and Stems: Too much water stop the roots from being able to absorb oxygen which leads to yellowing.
- Nasty Smell: Rotting roots can give off a very unpleasant smell.
Preventing Overwatering
- Watering Schedule: Let the potting medium dry after each time you water. Once a week should be enough water for your orchid but it will depend on your weather and humidity etc.
- Proper Drainage: Make sure the pot your orchid is in has lots of drainage holes so the water doesn’t sit at the bottom when you water (will cause root rot).
- Potting Medium: Use a mix that drains well. Something like sphagnum moss or bark is good for orchids and will help the roots to stay healthy.
3. Underwatering
Overwatering is mostly the bigger issue of the two and can also cause the stems to turn yellow. Not enough on water will cause your orchid to become dehydrated which will affect its health.
Indicators of Underwatering
- Wrinkled Leaves: Not enough water will cause the leaves to wrinkle and shrivel.
- Dry Potting Medium: The potting medium is dry even deep into the pot.
- Slow Growth: Your orchid may not be growing properly and not giving you any new shoots.
Addressing Underwatering
- Consistent Watering: Keeping to a schedule that lets you water regularly will make sure the potting medium stays slightly moist but doesn’t get soggy.
- Humidity Levels: Orchids do best in environments with 40 to 60% humidity. You can use a humidity tray or mist your orchid to get the humidity levels right.
4. Not Enough Light
Light is super important for keeping your orchid healthy. Both a lack of and too much light will result in yellow stems.
Effects of Light Imbalance
- Too Much Light: Direct light can burn your orchid and cause yellow or brown patches on the leaves and stem.
- To Little Light: A lack of light stops orchids from photosynthesizing properly and will lead to pale or yellow stems.
Optimizing Light Conditions
- Indirect Sunlight: Put your orchid in a spot that gets bright and indirect light. A north or east facing window is usually best.
- Artificial Lighting: If you aren’t somewhere that can get enough natural light then use an LED or fluorescent light to make up the difference.
5. Nutrient Deficiency
There are certain nutrients that orchids need to do well. If they don’t get enough of these nutrients then their stems can turn yellow.
Common Nutrient Deficiencies
- Nitrogen: Absolutely necessary for the growth of the leaves and stem. If there isn’t enough nitrogen then the leaves can turn yellow.
- Iron: Important for chlorophyll production. A lack of it will causes interveinal chlorosis, which is where the leaves turn yellow but the veins stay green.
Ensuring Proper Nutrition
- Balanced Fertilizer: Use a fertilizer that is specifically designed for orchids and dilute it based on the instructions on the pack.
- Regular Feeding: In the growing season feed your orchid every two weeks. When it’s dormant then you should ease off on the feeding.
6. Temperature Stress
Orchids don’t like it when the temperatures fluctuate a lot. Extreme temperatures, both hot and cold, will stress your orchid and result in yellow stems.
Ideal Temperature Range
Daytime: 65 to 75°F (18 to 24°C)
Nighttime: 55 to 65°F (13 to 18°C)
Managing Temperature
- Avoid Drafts: Keep your orchid away from cold drafts or heat sources.
- Stable Environment: Keep the temperature as consistent as possible and try to stop any sudden changes.
- Aphids: Small, green or black insects that you will find on new growth.
- Mealybugs: Found on the leaves and stems.
- Spider Mites: Tiny, red or brown dots.
- Manual Removal: Use a cotton swab dipped in rubbing alcohol to remove any pests you can see.
- Insecticidal Soap: Use something like a gentle insecticidal soap or neem oil spray. Doing so should keep any infestations under control. Make sure you test a small area first to see that the product isn’t going to damage your orchid.
- Regular Inspection: Try to inspect your orchids stems and leaves on a regular basis. Pests can be sneaky and easily missed. Getting to them early can save your plant from some serious damage.
- Soft Spots: If you see any mushy or soft spots on the stem that’s a good indicator of an infection.
- Brown or Black Spots: Dark spots or lesions aren’t uncommon to see on the stems or leaves.
- Bad Odor: A nasty smell is common with bacterial infections, especially from the roots.
- Remove Infected Parts: Trim off any areas that are infected. Disinfect whatever tools you’ve used between each time you trim so you don’t spread the infection.
- Improve Air Circulation: Orchids need a good amount of air to flow as it stops the mold or bacteria from growing as well. A small fan near your orchid can help with this.
- Use Fungicides Sparingly: If you can’t get rid of the infection then try using fungicide. But it should be as a last resort as orchids can be sensitive to the chemicals in them.
- Old Medium: Over time mediums like bark and moss can break down. When they do they become waterlogged and compacted.
- Wrong Medium Type: Orchids need a specific kind of medium that is going to let their roots breathe.
- Poor Drainage: If whichever medium you orchid is in doesn’t drain well it can mean the roots stay too wet and will eventually rot.
- Bark or Sphagnum Moss: Most orchids do very well in a coarse bark mix or sphagnum moss. These will both let the roots dry between watering.
- Repot Every 1 to 2 Years: repotting your orchid regularly will keep the medium fresh and stops salts and minerals from building up.
- Check for Drainage: Use a pot that has enough drainage holes so your orchid doesn’t end up sitting in water.
- Yellowing Tips: The edges of the leaves and stems may start turning yellow.
- Crusty Build Up: Too much fertilizer can leave a white coating on the surface of the potting medium.
- Stunted Growth: Too much fertilizer can cause orchids to struggle to grow properly or bloom.
- Dilute Fertilizer: Use a fertilizer but dilute it to half or even quarter strength, especially when your orchid is growing in the summer.
- “Weakly, Weekly”: Follow the “weakly, weekly” rule which is to fertilize once a week then flush the pot with plain water once a month to clear out any of the buildup.
- Skip Dormant Period: Lots of orchids have a period where they rest and don’t need any extra feeding.
- Orchids don’t like their roots being disturbed. When you move them it can set back their growth even if only temporarily.
- Change in Conditions: Light, humidity, and temperature changes can all impact an orchid’s health after a move.
- Adjustment Period: It can take a few weeks or even months for your orchid to get used to the new pot you’ve put it in or the conditions around it.
- Keep Conditions Stable: Give it the right light, humidity and temperature that it needs to help it recover fully.
- Minimal Watering: Don’t water it after you’ve done the transplanting as it needs some time to settle.
- Patience is Key: Time is important and your orchid will need that time to get used to the new environment it’s in before it can get back to it’s old health.
- Winter Light Drop: In the winter your orchid will be getting less light. This can cause some of the leaves or stems to turn yellow temporarily.
- Humidity Fluctuations: In the winter the air indoors can get dry and this can affect how hydrated your orchid is.
- Temperature Swings: When the seasons change from the warmer summer months to cooler autumn it can have an affect on how your orchid grows.
- Supplement with Artificial Light: If there isn’t much natural light then use a grow light to keep the light steady.
- Increase Humidity: Use a humidifier or humidity tray to keep the air moist during the months when it’s particularly dry.
- Keep Temperature Steady: You don’t want your orchid being near cold drafts or big temperature changes as the sea one change.
7. Pest Infestation
Pests like aphids, mealybugs and spider mites can damage orchids and the damage can result in yellow stems.
Identifying Pests
Controlling Pests
8. Fungal or Bacterial Infections
Bacteria and fungal infections can affect orchids. Even more so if you’ve been kept somewhere that is humid or damp.
These infections can cause stems, leaves or roots to change color and even rot.
Signs of Infection
Treatment and Prevention
9. Poor Potting Medium
The potting medium is very important too. A medium that isn’t right for you orchid any more can cause root problems that will eventually lead to a yellow stem.
Common Issues with Potting Medium
Choosing the Right Medium
10. Excessive Fertilizer
If you give your orchid too much fertilizer you run the risk of causing it to “burn” which will show up as brown or yellow leaves and stems.
Signs of Over Fertilization
Safe Fertilization Tips
11. Transplant Shock
If you’ve recently moved or repotted your orchid it might be stressed from doing so. This may result in the stems temporarily turning yellow as the orchid gets used to the new pot or spot it’s in.
Why Orchids Experience Shock
Helping Your Orchid Adjust
12. Seasonal Changes
The change it seasons also changes the light, humidity and temperature and this can affect an orchids appearance, including it’s stems.
Understanding Seasonal Impact
Maintaining Seasonal Balance
Final Thoughts
While yellow stems look bad it doesn’t mean your orchid is doomed and about to die. It more likely you’ll be able to heal your orchid and return it to full health if you care for it properly.
It might be it needs more nutrients, changes to how much or often you’re watering, an issue with the light or something else entirely. But as long as you pay your orchid close attention and give it what it need it will be fine.