Anthuriums are the plants I have struggled the most with browning leaves. The only Anthurium in my collection so far without any brown spots or brown tips has been my King Anthurium!
This article will examine some of the main causes of brown leaves on Anthurium and how to fix them.
1. Light Issues
Direct sunlight almost always needs to be avoided when it comes to indoor plant collection, and Anthuriums are no exception. If your Anthurium receives direct sunlight for a prolonged period of time, the leaves will most definitely form black spots where the sun has burnt the leaf.
Anthuriums are forest floor-dwelling plants, so a bright indirect light is not always necessary. It can grow well in medium indirect light. In fact, some anthuriums prefer to be in the darker areas of your home. Low light will not usually cause yellowing and brown leaves, but you may notice a decline in your plant’s growth rate.
2. Watering Issues
If you notice that your Anthurium’s newest leaf comes out looking fine but then turns yellow and brown along the edges with brown spots in the middle, this could be a sign of underwatering. The longer your plant sits without water, the more the yellowing overtakes the leaves. The yellowing will spread closer to the center of the leaf, and dry, crispy edges will soon follow.
These plants like to be kept moist, and dehydration is one of the most common causes of browning leaves.
If your Anthurium is pushing out a new leaf, this is the most crucial time to stay on top of your watering and make sure your plant has the moisture it needs.
If your Anthurium does not receive the care it needs while pushing out a new leaf, the leaf may come out looking disfigured and discolored. Many even advocate self-watering pots for Anthuriums as they are heavy water feeders.
I have found Anthuriums are quite resistant to root rot, but this doesn’t mean it can’t happen to your plant. I always recommend a chunky and well-draining soil mix for Aroids. For Anthuriums, I recommend going even chunkier and planting them in a Leca and bark mix.
Anthuriums require water on demand, and with this mix, you can continuously supply them with water without running the risk of root rot. This kind of soil mix is not for beginners, though! If you use this soil mix, you need to be on top of your watering routine.
3. Humidity & Temperature Issues
Anthuriums can adapt to low humidity but cannot tolerate inconsistent humidity. If your Anthurium is used to high humidity and then exposed to prolonged periods of low humidity, this will most likely result in leaves ripping, crisping around the edges, and forming brown, crispy spots on the leaf.
Your Anthurium will appreciate a controlled environment such as a grow cabinet or grow room/tent where temperatures and humidity levels stay more consistent. If you don’t have access to a grow cabinet or grow room, place your Anthurium in a warm room and close to a humidifier you regularly refill.
4. Fertilizing Issues
I’ve seen mixed reports on Anthurium feeding. Still, in my experience, they have benefitted from feedings when putting out new growth.
For most Anthurium collectors, watching a new leaf grow is why they fell in love with this plant. The leaf starts out very small, sometimes concerningly small, but then over the next week, it will grow 10 times bigger than what it started out as.
This growing leaf needs food to get big and strong! You can feed it by watering it with liquid fertilizer and even use a foliar spray. I also use a slow-release fertilizer in my soil mix.
If your plant doesn’t get the required amount of fertilizer, the growth of the new leaf can be stunted. In some cases, the plant will even kill off this leaf to conserve its energy.
5. Soil Issues
As with most Aroids, Anthuriums cannot be planted in a pot with waterlogged soil as this will lead to root rot and potentially losing your plant.
A sure sign that your Anthurium is experiencing root rot is if you notice the majority of your leaves starting to turn yellow, one by one, starting with the oldest leaf.
If you suspect your plant has root rot, I suggest taking it out of the pot, cleaning off all the soil on the roots, and assessing the damage. Your plant’s roots should be white or green. If they are brown and mushy, they have rot.
Remove all rotten roots. If you have some healthy ones left, you can re-pot your Anthurium in new soil. I recommend using a clear plastic pot with drainage holes if your plant is in soil, as this will help you keep an eye on the roots.
Anthuriums love Leca and Pon, but if you are uncomfortable with this method, consider using a standard aroid mix, as semi-hydro planting methods can be quite tricky.
6. Pests and Diseases
After Alocasias, Anthuriums are spider mites’ favorite snack! You will want to keep a close eye on your Anthuriums and look out for spider mite damage.
It is easy to spot spider mite damage. You will see lightly colored pin prick spots on the leaf. If you suspect spider mites, take a closer look at the crevices of your plant’s leaves and where the petiole meets the leaves. If you notice tiny white or red spots moving around, then you’ve got spider mites!
Get your hands on an insecticide with bifenthrin as the active ingredient, follow the instructions, and don’t be afraid to douse your plant with it. You will need to repeat the process a few times.
Extensive spider mite damage doesn’t often destroy established leaves, but it can leave them looking quite unsightly. However, I have noticed that extensive spider mite damage on new, growing leaves can cause the leaves to die.
Bacterial blight looks like someone has taken a bite out of your leaf, sometimes accompanied by brown spots forming near the center of the leaf, and new leaves start to emerge looking deformed.
Bacterial blight damages your plant rather quickly. Before you know it, 30% of the leaf has turned brown and died. If you think your Anthurium has blight, isolate the plant as soon as possible because blight is quite contagious.
I suggest cutting off the infected leaf all the way to the base of the petiole. You can also spray your plant with bactericides. I lost my entire Anthurium Forgetii to bacterial blight in the space of 3 months.
Fungal infections are mostly caused by a lack of airflow, damp soil, and excess water left on the leaves for long periods.
If your Anthurium’s leaf has started developing 1 – 2 cm yellow spots placed randomly around the leaf, you may have a fungal infection.
The best way to control fungal infection is to increase airflow in the room that your plant is in. Use a fan to move air around and open a window to ensure your plant gets some fresh air.
7. Seasonal Change and Environmental Fluctuations
Suppose you notice that your Anthurium leaves are browning along the edges and not in the middle, and you are in a change of seasons. In that case, this is an almost sure sign that your Anthurium is experiencing some shock from the change of season. This could be a drop in humidity or increase/ drop in temperature.
When you know the season is changing, you need to adjust your plant care accordingly.
Keep in mind if you move your Anthurium from its usual spot, it may freak out a bit and lose a leaf or two. Importing Anthuriums is very common, and they will take a while to acclimate – even lose all of their leaves like our Queen Anthurium. We put the remaining chunk in semi-hydro, and it has finally regrown a tiny leaf after 7 months.
FAQs About Anthurium Leaves Turning Brown
Should I remove brown leaves from my Anthuriums?
It depends on whether they bother you or not. I tend to leave the brown leaves on my anthuriums as I feel they are still giving nutrients to the main plant, and I don’t mind how they look.
None of the above is wrong with my Anthurium, but the leaves are still browning. What could the issue be?
This could be due to the natural aging process of the plant losing its old leaves. This is completely normal and usually happens to the outer and oldest leaves on your plant.
Is there a way to save a leaf that has turned brown?
Once a leaf has turned brown, there is no way to make it “heal” and turn green again.
How to prevent brown leaves on Anthurium?
Anthurium need a certain type of environment to thrive. They are not the biggest drama queens of the indoor plant collection. However, they tend to be quite finicky if not looked after correctly.
You need to do your best to give your anthuriums water right when they need it and supply them with steady humidity and temperature levels. Consistency is key!