Aloe vera plants are widely grown and widely used for their medicinal properties. So, it’s a bit on the nose that a plant that’s supposed to be an emblem of health is looking kind of sickly.
But even aloe plants get sick sometimes, and an aloe plant turning brown isn’t out of the ordinary, especially if said aloe plant is neglected or its keeping requirements aren’t properly met.
The key is identifying the problem and making necessary adjustments or applying appropriate treatment, where disease or pests may be the culprits.
If you’re worried about the health of your aloe plant, in this article I’ve summed up all the possible causes for an aloe plant turning brown and offered several solutions to these problems.
Here’s a short preview to why your aloe vera plant may be turning brown:
- Bad watering schedule – both excess water and insufficient water can cause browning.
- Improper temperatures – usually, exposure to extremes, extreme heat or extreme cold.
- Excessive sunlight – direct sunlight can scorch the leaves.
- Pest or disease related browning – some pests or diseases will cause brown spots or browning.
- Fertilizing issues – adding too much fertilizer will burn the plant’s roots and turn the leaves brown.
- Other causes – most commonly damages like cuts, scrapes, bent leaves can also cause browning leaves.
Let’s look at each of these issues one-by-one and see how they can be solved to get your aloe plant back into great shape.
Does Watering Cause Leaves to Turn Brown?
In itself, normal watering does not turn your aloe plant brown. Only when you’re excessively watering or withholding water for a prolonged time should you worry about an aloe plant turning brown.
Therefore, both overwatering and underwatering can be associated with browning leaves, but in most cases, overwatering is a much more common problem than underwatering.
It’s important to understand that aloe plants are succulents and even though they don’t hold as much water as desert cacti, they still have a pretty good water holding capacity, which means that overwatering can really do a number on them.
How to Manage Overwatering Issues?
Make sure your aloe plant is potted in well-draining soil (e.g. commercial soil designed for succulents is great), and that the pot has draining holes on the bottom.
Favor terracotta or clay pots over plastic pots, since plastic will hold water, making it much harder for the soil to dry, while clay and terracotta will absorb it, giving the soil a chance to dry.
Before watering, always check that the top of the soil is dried out. If not, hold off the watering until the top 2 inches of soil is dry.
Stick a finger into the soil if you can’t decide based on visual inspection. If the top layer is still moist, you’ll need to wait for it to dry out more before you can safely water your aloe plant.
If overwatering is causing issues with your aloe, it’s important to act fast as any delay can end up killing your plant. You must quickly repot your plant, remove any rotting or squishy roots, keeping only the healthy roots.
It’s equally important to recognize the early signs of overwatering — squishy leaves and soggy spots.
Underwatering can also be problematic and browning leaves can be a symptom of underwatering.
The first sign of underwatering is browning at the tip of the leaves. Eventually the leaves will shrivel and shrink.
Just because aloe plants can tolerate some drought, it doesn’t mean they can go without water for extended periods.
How Temperature Variations Can Cause Leaf Browning
Sudden excessive heat or exposure to too much cold can also cause browning on your aloe plant. Temperature shock of any kind is another thing you can add to your list of potential causes of leaves turning brown.
If the damage is too big (e.g. the plant has frozen or it was left out on the burning sun until it dried out), there’s not much you can do to salvage the plant. If it’s frost-bitten, you can take it inside and see how it goes. Same goes for a sun-burned plant — take it out of the sun, give it a good watering, and hope for the best.
How to Fix Temperature-Related Browning?
Because exposure to extreme temperatures can often cause irreversible damage, prevention is key. And the way to prevent these things from happening, you should always keep an eye on indoor and outdoor temperatures and make sure they fall within the acceptable range for your aloe plants.
Ideally, aloe plants should be kept in temperatures between 55-80°F. Temperatures outside this range can cause damage, especially if they’re exposed to those temperatures for prolonged periods.
If you’re taking your aloe plant outside during the summer, make sure to slowly acclimate it to the summer heat. Likewise, during the cold season, protect your aloe plant from cold drafts and sudden temperature chances.
It’s also important to keep the plant away from air conditioning units, heating vents, cold windows, and too much direct sunlight indoors and out.
Managing Excess Sun Exposure
While aloe plants need 6-7 hours of sun daily, they prefer partial indirect sunlight to full sun exposure. Exposure to excessive sun will slowly turn the leaves yellow, then brown spots may appear on the surface of the leaves, until the leaves will finally fall off.
If you’re keeping your aloe plant in a windowsill where it gets too much direct sunlight, consider moving it away from the window or to a window in a location with less exposure to direct sunlight to see how it fares.
Just don’t do a complete 180 turn and place your aloe plant in a shady area with little to no sun. These plants do need quite a bit of brightness, so favor indirect bright light over direct sun or complete shade.
Pest or Disease Related Leaf Browning
Both pests and diseases can cause browning leaves on your aloe vera plant. The pests to look out for include mealybugs, fungus gnats, and mites. If left unchecked, these can all damage your plant.
Cleaning the leaves with water or using a proper insecticide can clear up pest-related problems. Some pests like fungus gnats can be prevented by not allowing the soil to get too wet or soggy.
Diseases like leaf spot disease or leaf blight disease can also be culprits in creating brown spots on your aloe plant.
One of the chief causes of these fungal diseases are overwatering, which creates an excessively moist soil environment that favors the growth of fungi.
The watering recommendations for aloe vera plants as well as potting and soil recommendations I discussed above will help prevent these diseases, which are often fatal to your plant.
Fertilizing Issues that Lead to Leaf Browning
If all the requirements of your aloe vera plant are being met — enough light, quality soil, optimal watering, etc. — extra nutrients in the way of fertilizer are rarely needed.
Therefore, it’s easy to see how overzealous indoor gardeners may go overboard with the fertilizer and end up “burning” the plant’s roots, which will eventually lead to brown leaves.
I recommend against fertilizing your aloe plants. If you do think it needs a little pick-me-up, you can add a half-strength succulent fertilizer once a year in the spring.
But be sure to check whether your potting mix has any fertilizer already in its mix. If it does, don’t bother adding extra fertilizer, you’ll do more harm than good.
What if you’ve accidentally added too much fertilizer to your aloe plant? Is the situation salvageable? You can try to flush the soil for several minutes with water to wash away as much as the fertilizer as possible and allow all the water to drain.
Other Causes of Browning Leaves
Sometimes, the cause of a brown leaf on your aloe plant isn’t because of a disease, pest or improper conditions, but something much less complicated like damage caused by rough handling.
If you have pets, they too might damage your aloe plant by biting on the leaves or scratching the leaves. Usually, a callus forms over at the site of the injury, so the browning you see on the aloe leaves may be because of that.
As you can see, there are several causes to why your aloe plant is turning brown. It’s important to check your plant for all these issues, so you can narrow down the cause and make arrangements to get things back to normal.
Pest and diseases should be treated with the appropriate pesticides and fungicides. Make sure you review your watering schedule, check if you’re keeping your aloe at the right temperature, if the soil is right, and whether you’ve done anything lately that could have damaged the plant (rough handling, damage by a pet, over-fertilizing, etc.).
Some of these problems can be easily fixed by making proper adjustments, others may cause irreversible damage to your plants. Therefore, it’s important to identify problems and make necessary changes as soon as possible.