When I was thinking of getting my first indoor houseplant, orchids topped my list of considerations.
And reasonably so, they have colorful blooms and produce some of the best fragrances.
The other reason was that orchids are the second largest family of flowering plants, only second to Asteraceae.
So, they are easy to come by and are relatively inexpensive than most indoor houseplants.
While orchids are easy to maintain and generally resilient to bad weather, sometimes their stems may turn yellow.
In this article, I delve into possible causes and how to prevent the yellowing of orchid stems.
Why Is My Orchid Stem Turning Yellow?
Orchid stems turn yellow due to overexposure to direct light, overwatering, or bacterial and fungal infections. But, if it’s only the part of the stem holding the bloom that has turned yellow, the flower spike is dying out. Cut down the yellow flower spike to let it dry out and fall off by itself.
The Main Cause of Yellowing in Orchid Stems is Overexposure to Excess Light
In determining why orchid stems turn yellow, we should understand that most people use the term “stem” to refer to either the flower spike or the actual stem.
Under normal circumstances, green pigmentation signals good health in both.
For most plants, sunlight is an essential component of growth and healthy development.
It’s used in photosynthesis to produce food for the plant’s sustenance and growth.
Therefore, the general expectation is that the more plants stay exposed to light, the more food they make and the healthier they stay. However, this assumption does not hold up for orchids.
In most orchids like phalaenopsis, overexposure to direct light causes scorching. If this happens repeatedly, parts such as stems, spikes, and leaves gradually turn yellow.
Orchids are tropical plants. They thrive well in the shade of large trees with deep canopies, allowing very little light to enter through.
Therefore, they are not used to lengthy exposure to direct sunlight. Too much light triggers a burning effect, which eventually causes the yellowing of stems and spikes.
Other Reasons Why Orchid Stems Turn Yellow
Besides excess light, here are other common causes of yellowing of orchid stems:
With houseplants, we should water them only as much as they need. Overwatering or underwatering can cause stems to turn yellow.
As soon as any abnormal yellow pigmentations begin to appear on orchids’ stems, the first thing we should do is to check the soil in their pots.
When orchids don’t get enough water, they instinctively shed their leaves to conserve the little water they have by minimizing transpiration.
As a result, the plants’ regular food production will be hindered. This causes stems, spikes, and other green parts to turn yellow or brown.
Too much water is just as dangerous as water deficiency. Poor soil drainage leads to water-logging around the orchids’ roots.
If this continues for a long time, the roots will drown, lack oxygen, and die. Again, this hinders food production, causing yellowing or discoloration of stems.
Aging can also cause yellowing of orchid stems, especially spikes. As most orchids age, the tips beneath the bloom occasionally turn yellow.
This process is part of the plant’s natural cycle and should be no cause for alarm.
After some time, the spikes will dry up and drop off by themselves. Alternatively, we can trim them back to the main stem.
Doing so promotes faster regrowth and rapid blooming.
Orchid stems may also turn yellow if the plant is not adequately receiving the right proportions of all the nutrients it requires.
The two most common nutrient deficiencies synonymous with the yellowing of orchid stems are excess calcium and inadequate nitrogen.
Different orchids require different nutrients. Before we uproot or kill any orchid due to a yellow stem, we should adequately research and diagnose the cause.
I recently acquired a soil kit for at-home soil tests, and it has significantly helped me identify my orchids’ nutritional needs and keep them healthy.
Effects of Orchid Stems Turning Yellow
Based on my experience and discussions with friends, here are some reasons why no houseplant owner would love their orchid stems to turn yellow:
- Yellowing of stems can cause demoralization. I remember blaming myself and trying to find out what I didn’t do right when my orchids’ stems first turned yellow. I had done everything—from adequate watering to proper lighting and regular soil testing—and continually wondered why all these efforts bore no fruits.
- Yellow stems jeopardize the aesthetic appeal of orchids, which is one of the main reasons we grow these houseplants. The best orchids are those with a green stem and colorful blooms.
- Yellow spikes can also hinder healthy blooming
The Solution to Yellowing in Orchid Stems
As I have highlighted, the causes of yellowing in orchid stems are different. So, there’s no across-the-board solution.
Instead, we should examine each case, identify the problem, and implement the correct remedy.
Here are some possible solutions I may consider:
Adjust the Orchid’s Environment
Where yellowing of the stem is due to overexposure to direct light, the solution is to move the plant to a different position with limited light reach.
Alternatively, you can use artificial light that is easy to adjust and control.
Use Clean Water
Excess calcium in the soil causes stem yellowing. In most cases, the extra calcium is introduced into the soil by calcium-laden water.
So, using clean water is also another way to prevent orchid stems from turning yellow.
Cut off the Yellow Spikes
As I pointed out, the yellowing of spikes indicates that they are done supporting life.
To eliminate the yellow pigmentation and encourage rapid regrowth, we can cut off the tips.
Frequently Asked Questions About Why My Orchid Stem Is Turning Yellow
How do I stimulate blooming in my orchid?
By putting it in a cold room, preferably by the window. When the sun sets, the heat will reduce, and the resulting cold will induce the orchid to bloom.
Should I cut off or uproot orchids with yellow stems?
Yellowing of stems is a common phenomenon in orchids. When it happens, we shouldn’t rush to kill the whole plant. Instead, we should only cut off the yellowed stems.
These are the tips that have helped me maintain and keep my orchids healthy.
We should note that it’s easier and better to prevent the yellowing of stems before it happens.
Otherwise, we may notice the change in pigmentation when it’s already too late.
Marcel runs the place around here. He has a deep passion for houseplants & gardening and is constantly on the lookout for yet another special plant to add to his arsenal of houseplants, succulents & cacti.
Marcel is also the founder of Iseli International Commerce, a sole proprietorship company that publishes a variety of websites and online magazines.