Aloe plants sometimes have hints of blue or gray in addition to their green foliage, but they certainly should not appear brown. If your aloe plant has spots or patches turning brown, knowing what’s likely causing the discoloration is the first step in stopping it.
An indoor aloe plant turning brown can be suffering from moisture fluctuations, nutrient deficiencies, sun scorch, fungal diseases, and excess fertilizer. Many of these issues are correctable.
You may have yet more questions about your brown indoor aloe. Can a brown aloe turn green again? What does an overwatered aloe plant look like? I’ll answer all those questions and more in this article.
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5 Reasons Your Indoor Aloe Plant Has Turned Brown
The aloe vera is a succulent, which some beginner indoor gardeners can forget.
As a succulent, those elongated, fleshy leaves of your indoor aloe plant hold onto water for as long as the plant needs it.
The timeframe can be days to weeks, although humidity and heat absolutely play a role in how long the water retention lasts.
You should water your indoor aloe plant about weekly in the summer and maybe every two to three weeks in cooler seasons.
If you didn’t know that, then you may very well be watering your aloe plant too often. What does an overwatered aloe plant look like?
The fleshy leaves of your indoor aloe can develop blisters as the cells absorb too much water. You may also spot mold developing on the surface of the soil, which will be white or grayish.
Further, leaf browning will occur. The fleshy leaves can become mushy, and the stems of the aloe plant can go soft.
At that point, it can become difficult for your plant to hold itself up, and the succulent could collapse.
An underwatered aloe vera doesn’t fare much better. Its leaf edges will dry out and become brown or yellow. The entire plant will droop as well.
If you had to, it’s better to underwater than overwater your aloe plant (it is drought-tolerant, after all), but neither is good in the long run.
You know what else isn’t good for an indoor aloe plant? Nutrient deficiencies.
All plants rely on three macronutrients to support a healthy, long life. The first of these is nitrogen.
Nitrogen is the most important nutrient of the three. Without nitrogen, your aloe plant cannot make proteins, as it’s lacking the amino acids that nitrogen produces. If the aloe vera doesn’t have proteins, then the plant can’t develop new tissue.
Further, a major part of chlorophyll is nitrogen. More so than just giving indoor plants their appealing green color, chlorophyll allows your aloe plant to absorb energy from sunlight.
In other words, growth can’t occur without nitrogen.
Phosphorus is the second macronutrient an indoor plant needs. This nutrient allows indoor plants to produce seeds, roots, flowers, and fruits.
Okay, so the aloe vera doesn’t bloom, and it won’t produce anything edible on its leaves (the leaves themselves are technically edible though). However, your indoor aloe plant needs strong roots or it won’t last very long.
The third plant macronutrient is potassium. Without potassium, a plant’s cell walls are thin and flimsy. If the plant is diseased or injured, it might not hold up as well as a plant that’s getting more potassium and has thicker walls.
How do you know if your indoor aloe plant is nutrient-deficient? You can look out for all sorts of signs.
When you pour water into the aloe vera’s pot, that water evaporates very quickly even in cooler months.
The thick leaves will have dry patches or spots. The edges of the leaves can be very dry and brown and may also feature yellow discoloration.
It’s easy to make fertilizer mistakes when it comes to the aloe plant. You only need to fertilize the indoor plant monthly.
You can use a succulent fertilizer or a liquid fertilizer with a 10-40-10 balance of nutrients. The 10s represent potassium and phosphorus respectively while the 40 is for nitrogen.
The more than 500 aloe vera species grow in arid, semi-tropical, and tropical environments around the world. That can cause some indoor gardeners to assume the aloe plant loves bright light.
That’s just not true.
More so, prolonged time in the sun can lead to sun scorch aka leaf scorch.
This condition causes the plant tissue from the leaf tips to the margins to become brown. The veins within the leaves can darken or turn yellow.
Wilting will soon follow, and the leaf can even fall off, and that’s true of thicker leaves like seen in an indoor aloe plant.
Keep an eye out for red patches near the tips of the leaves; this area can also be brown. These are signs of sun scorch.
The rest of the leaves can fade to a very pale green. Sunspots can develop as well, which are brown spots across the aloe plant’s foliage. These spots are quite hard to miss!
If your aloe vera has sun scorch, you need to bring it out of the sun immediately. Shield it from direct light for the next day at least and maybe the following day or two as well.
Any damaged leaves are as good as dead, so you’ll have to prune them using clean gardening shears. Always disinfect your trimming tools with bleach or 70 percent isopropyl alcohol to prevent the spread of disease.
In the future, the aloe plant thrives best in bright, indirect light like that from a curtained window.
Root rot, which I touched on before, is technically only one fungal disease of several that can befall the indoor aloe plant.
You may also see diseases such as soft rot, fungal stem rot, and leaf rot.
Soft rot, which is either fungal or bacterial, is caused by fungi or pathogens. The cell wall structure of the plant breaks down as the fungus or pathogen releases enzymes.
As plant tissue degrades, it develops a watery, soft texture.
Like many fungal and bacterial diseases, soft rot has no treatment.
Fungal stem rot occurs when the Pythium, Fusarium, or Rhizoctonia fungi spread to your aloe vera. The stems will manifest symptoms first and may potentially become unable to support the plant.
What’s worse is that stem rot is a long-living disease. Once it reaches the soil, the fungi that cause stem rot can live for five years.
The only treatment is to apply a fungicide, and even that’s not guaranteed.
Leaf rot or leaf spot will cause spots to form on the fleshy leaves of your aloe vera that are red, orange, or yellow. The spots will later release spores in those same colors. The spores can possibly transfer to other nearby plants.
If your indoor aloe plant is affected by leaf spot, then the only option is to prune away the infected leaves and use a fungicide or neem oil on the rest of the plant.
Did you think that sunlight is the only thing that can burn your aloe vera? While it’d be nice if that was true, it isn’t.
Fertilizer burn can also occur, especially if you overfeed your indoor aloe plant. Excess fertilizer application will cause noticeable discoloration, with the leaves of your aloe turning brown or yellow.
The leaves will also begin to sag. You might spot white crust across the aloe’s soil, which is fertilizer on the surface.
How does fertilizer burn happen?
Well, like anything in this life, when you overdo it on good things like macronutrients and micronutrients, your plant is no longer healthy. The salts in fertilizer don’t help the aloe either.
So what can you do for your poor indoor aloe plant if you suspect you’ve fertilized it too much? You’d have to lift your aloe vera from its pot and rinse it using clean water.
You can flush the soil with clean water to wash away the salts and fertilizer residue. If you want to be even more cautious, then you can replace the aloe’s pot with fresh soil that has no nutrients in it.
If the fertilizer burn didn’t lead to serious side effects, then your aloe plant should be okay. In most cases, brown aloe vera plants can become green again, but it takes time, so be patient!
To reiterate, in the future, fertilize the indoor aloe once per month and only during the active growing season.