Anthurium leaves yellowing can happen regularly. In the 6 years of owning an Anthurium Andraeanum (often called flamingo lily or flower) I’ve encountered the issue several times and from my experience, it is quite an easy thing to correct.
Usually, an Anthurium will start to show yellow leaves when the conditions are not optimal or as part of the natural lifespan of the leaves. The conditions include things such as overwatering, insufficient humidity, too much sunlight and several other factors.
In this article I’ll take you through 10 things that can lead to Anthurium leaves yellowing, as well as what you can do to quickly fix the problem if you run into it.
10 Reasons For Anthurium Leaves Yellowing
The first step to fixing yellowing Anthurium leaves is to determine what causes them in the first place.
Through several years of owning an Anthurium Andraeanum I’ve personally dealt with a lot of the problems in the list below, so I’ve added a few of my own tips where applicable for the best results.
Anthuriums enjoy a humid environment, but they do not have a large requirement for water.
If you overwater your Anthurium it will cause the leaves to turn yellow pretty quickly as the roots will struggle to absorb the necessary nutrients from the soil.
I like to water my Anthurium once per week during the growing season and once every fortnight in the colder months. This will vary depending on where you live, however, and if you live in a warmer environment then twice per week during the summer should be fine as long as the soil is well-draining.
2. Improper Soil Mix
Ensuring your Anthurium has a well-draining soil mixture is crucial to its growth, as it will maintain the correct level of moisture in the soil alongside a correct watering schedule.
If your soil mix doesn’t drain well it can cause the same issue as overwatering (leading to yellow leaves), and fact makes it even more likely to happen.
The soil must also be very light, and if you want to make your own mix you can use equal parts peat, pine bark and perlite. I have a layer of sphagnum moss above the soil on my Anthurium, as this holds moisture well and prevents the soil below from drying out as quickly.
3. Fertilization Problems (Too Much Or Too Little)
Over and under-fertilization can lead to yellowing leaves on an Anthurium.
Under-fertilization means the plant is not getting enough essential nutrients which are key for proper growth. This will cause leaves to turn yellow over time, as well as slow down the overall growth of the Anthurium.
Over-fertilization can also cause the yellowing of leaves, so you should avoid this as well.
In general, Anthuriums don’t require a lot of fertilizer as they grow quite slowly anyway. I don’t give my Anthurium any fertilizer during the colder months, and apply a complete liquid fertilizer (with sufficient NPK) about once per month in the summer.
4. Low Humidity
Anthuriums are native to Colombia and Ecuador and thrive in high-humidity environments. This is the reason why they prefer to be kept in bathrooms or kitchens where the humidity levels are higher.
You should aim to keep the humidity at least above the 50% or 60% level for optimal growth. They will tolerate lower humidity, but the leaves may start to turn yellow as they lose moisture more quickly than in a humid environment.
If you want to increase the humidity consider using a pebble tray or humidifier. Misting your plant will only increase the humidity in the short term.
5. Temperature Problems
Cold drafts can cause tropical plant leaves to turn yellow, so if your Anthurium is near to a drafty window, door or vent you might want to consider moving it somewhere with a more consistent temperature.
Anthuriums do best with temperatures between 75°F and 90°F (roughly 23°C to 32°C) during the day, and down to around 60°F (around 15°C) during the night time. If the temperature is consistently outside of this range it can also lead to yellow leaves.
6. Part Of The Plant Cycle
Some leaves on your Anthurium will simply turn yellow due to age, and this isn’t a bad thing.
If you notice only one or two leaves turning yellow every so often it is probably not a bad thing. I have to prune yellow leaves from my Anthurium probably once every couple of months due to this.
7. Root Rot
Root rot can occur due to overwatering or due to fungus in the soil, and both types will cause the leaves to turn yellow.
- Overwatering – If the roots lay in excess water for extended periods of time they can start to rot due to a lack of oxygen. Eventually, the roots will die, and the rot can spread to other roots even after the problem is fixed.
- Fungus – Root rot can also be caused by a fungus that is activated by overwatered conditions in the soil. When activated it attacks the roots, leading to the aforementioned problems.
There are a lot of different Anthurium diseases, and its well beyond the scope of this article to explain all of them and how they work.
They are one of the more common reasons why your Anthurium may start to exhibit yellow leaves though, and the two main culprits are bacterial leaf blight and bacterial wilt.
Due to their complexity, they are very difficult to deal with at home. I would advise following the steps in this article for your best chance of getting rid of any disease that may be affecting your Anthurium.
Anthurium, like most houseplants, is quite vulnerable to pests – especially when grown outdoors.
Common pests include mealybugs, aphids and mites. They will typically remove plant sap rather than going for the leaves as they are too thick, and will cause the overall health of the plant to deteriorate over time.
If you spot pests on your anthurium you can wash them away, or use soap or spray to get rid of them. In serious cases, you may need to use a pesticide, but this can affect the ability of the plant to grow flowers.
10. Improper Sunlight Levels
Anthuriums are very similar to pothos in that they require bright but indirect light for optimal growth.
Too much direct sunlight can scorch the leaves, leading to yellowing. Too much shade, however, will reduce the amount of sunlight that your Anthurium receives which can have the same yellowing effect as the leaves will not be able to photosynthesis as well.
What About Yellow Spots On Anthurium Leaves?
When yellow or brown spots develop on Anthurium it is usually due to one of two things:
Most of the things that cause the yellowing of Anthurium leaves can also cause yellow spots as well. The most common of these are under fertilization and direct sunlight.
If your Anthurium starts to form yellow spots, try moving it away from any direct sunlight and increasing your fertilizing schedule to give it a healthy dose of nutrients. Remove the affected leaves as soon as possible, as it could also be a bacterial issue.
Bacterial Leaf Blight
I touched on this briefly before, but you may be more likely to first notice bacterial leaf blight by small yellow spots on the leaves of your Anthurium that will quickly turn brown.
This will spread over time, causing the stems to turn brown, eventually killing the entire plant if not treated properly. Research shows that the introduction of bacterial blight to Anthuriums can lead to a 50%-100% loss of plants.
As I mentioned previously, use the steps in this article to identify and treat bacterial infection on your Anthurium.
How Do You Fix Yellow Leaves On An Anthurium?
Once your Anthurium starts to show yellowing leaves on a regular basis you first need to identify what has gone wrong.
Use the list above to check which conditions are not being met, and don’t forget that it can sometimes be part of the life cycle of the plant and not something to worry about.
If multiple leaves turn yellow at a similar time you probably aren’t providing the right conditions or there is a disease or pest problem affecting your Anthurium.
Once you’ve identified and dealt with any potential issues you shouldn’t remove the yellow leaves right away in most cases (unless there is a pest or fungal disease, of course). Instead, let the entire leaf turn yellow and then trim it away carefully, leaving as much of the stem as possible if it looks healthy.
This will allow your Anthurium to absorb any nutrients left in the leaf before it is removed. Once you have trimmed the leaves, you shouldn’t have any unusual yellowing of leaves afterwards assuming the above issues have been addressed.
From my experience, most yellowing of leaves on Anthuriums is simply due to the ageing of the plant.
If several leaves become yellow in a small time frame you may be looking at one of the ten issues laid out in this article.