In this article I cover the subject of aloe smell. I outline what aloe should smell like and what it smells like when there is a problem with the plant or with cut leaves. I also outline what aloe vera latex (the aloe vera gel used in common household products) should smell like and what it smells like when it has gone bad.
The aloe smell test
In order to determine if your aloe plant, or cut aloe leaves, are actually smelling bad or if the problem is just that you find the natural scent of this succulent to be offensive to your nostrils we need to delve into how an aloe plant is suppose to smell. To do this I need to give you a brief background of this flowering perennial.
The aloe plant is a tropical flowering succulent that grows in parts of Africa as well as a few other places like Madagascar, the Arabian Peninsula, Jordan and some islands in the Indian Ocean like Comoros, Réunion and Mauritius.
This succulent has evolved over time to be able to handle long periods without water, while growing in rocky areas or in sandy-type soil (see our aloe plant soil guide) while simultaneously experiencing strong direct sunlight during the day.
Aloe is a hardy plant that grows in, what is for most other plants are, inhabitable conditions. In its native habitat an aloe plant can survive a lot of hard knocks but even this hardy plant is not immune to the negative effects of a bad care routine when grown as a houseplant. And, one of the key ways to tell if the plant has not been getting the proper care is through its scent.
But, before we go into how a bad aloe plant smells, we need to look at how a healthy aloe plant should smell.
Does aloe smell good?
With many houseplants grown for their pleasant fragrance you may be mistaken in believing that aloe plants are so popular across the US because of their smell. Are these succulents grown for the smell of their blooms or foliage? Does aloe smell good?
Aloe does not smell good to most people. Unless you like the smell of onion you will not like the smell of aloe plants or the latex contained within the leaves. However, the odour from an aloe plant will not be strong unless the plant is in some kind of distress.
Although an aloe plant does not smell particularly good it should not give off a very strong pungent odour. Let’s face it, if aloe plants smelled really bad they would not be so popular as American houseplants! So why do some aloe plants smell so bad?
If your aloe plant smells very bad, or the smell from the latex (gel) harvested from an aloe vera leaf smells bad, you should immediately investigate the reason. And, once the cause is found you should treat your plant appropriately. I give care guidance below for aloe plants that smell really bad due to problems with the plant.
What is aloe supposed to smell like?
Although aloe is not suppose to have a strong smell, being a member of the same plant family as the common onion it does have a slight odour. But what exactly is aloe supposed to smell like?
Aloe should not have a strong smell but as it belongs to the same plant family, Amaryllidaceae, as onions, garlic, scallions, shallots, leeks and chives it does have an onion-like scent. The scent is most apparent when the leaves are cut for latex harvesting (as with aloe vera).
Aloe plants broadly belong to the Liliaceae family which includes lilies, and so it should come as no surprise that the smell from the plant can be unpleasant to many people – lilies are renowned for the unpleasant smell of their beautiful flowers.
So, being part of the same plant family as the onion and being broadly connected to the same plant family as stinky lilies, it stands to reason that aloe plants will not smell particularly pleasant.
What do aloe flowers smell like?
So what are the flowers of an aloe plant suppose to smell like when the plant goes into bloom?
There should be no detachable smell from an aloe flower. The plant itself can smell, especially when the leaves are cut, as it belongs to the same family as the onion but the flowers themselves should have no smell. If the flowers of an aloe plant smell bad it could be an indication that there is a problem with the plant.
Although aloe is not suppose to have a strong smell, being a board member of the Liliaceae family and a direct member of the Amaryllidaceae family (like amaryllis though amaryllis flowers smell quite nice) it does have a slight odour. Lillies are also members of the Liliaceae family are are well-known for their beautiful, but unpleasantly smelling blooms. While onions and garlic are members of the Amaryllidaceae family and we all know what they smell like.
It is therefore only to be expected that aloe would have a somewhat unpleasant odour with its genetic background.
All aloe plants will bloom with flowers that produce no noticeable smell. This means that an aloe vera flower smell is also undetectable. If the flower is giving off an odour then it will mostly likely be unpleasant and this is an indication that the plant has a problem (see later sections below).
Read through the rest of this article to determine what is wrong with your aloe plant and take the suggested actions to fix the problem if your plant is giving off a strong smell.
What does bad aloe smell like?
How do you know if your aloe plant, or its gel, has a strong smell because it is experiencing problems or if the plant just smells as it is supposed to … what does bad aloe smell like?
Bad aloe smells like very strong garlic. Although aloe naturally has an onion or garlic like smell, the odour will be much stronger in a plant that is experiencing problems, or in a product where the aloe gel it contains has gone bad.
If your aloe plant smells really bad then you know the plant has a problem and you should investigate the cause immediately.
Why does my aloe plant stink?
So why do aloe plants go bad and what causes them to stink?
An aloe plant will stink when it has a serious rot problem. The most common cause for a strong unpleasant aloe plant smell is root rot. Root rot will start at the roots but will quickly spread throughout the plant causing the foliage to become mushy and give off the strong odour.
Root rot is one of the most serious problems an aloe plant can have. If you do not take immediate action to treat the plant you will lose it completely in a very short time period.
Root rot is caused by overwatering your plant. As I covered in my aloe plant watering guide, these succulents require very little water. They grow naturally in desert-like environments where water is scare.
Not only have they evolved to do without water, which normally comes from rainfall (causing aloe plants to dislike water landing on their leaves and to prefer being watered from the bottom) but their natural habitats also experience many days of strong prolonged sunlight which further reduces water in the environment through evaporation. See my aloe plant sun and light needs article for information on where to place your aloe houseplant so it gets enough light.
As aloe plants have evolved in water-scarce environments an aloe houseplant should normally only be watered once every 3 weeks. If you have been watering your aloe more than this then the likelihood is you have been overwatering the plant and it has developed root rot – hence the strong unpleasant smell.
To investigate for root rot first look at the stem of the leaves. If the leaf stems are blackened, or they are becoming brown and mushy, then the plant definitely has root rot. Other indications of root rot can be a yellowing of the leaves or leaves that begin to turn white (see our aloe leaves guide for more on this) or you might see a browning of the leaves.
Even if there are no clearly visible signs of root rot I strongly urge you to remove the plant from its pot and investigate the state of the roots, if your plant smells bad.
I have detailed instructions for identifying root rot and treating it in this section of a previous article that deals with treating root rot in african violets. Although the plant being treated is different the procedures and processes are exactly the same for aloe and aloe vera plants with root rot.
Why does aloe vera smell bad?
Aloe vera belongs to same family as all other aloe plants. The causes for a bad smelling aloe plant that I covered above are the same causes for a bad smelling aloe vera plant.
Aloe vera belongs to the same plant family as onions and garlic so it naturally has an onion-like smell. This smell should not be pronounced though. If the plant has a very strong odour it is an indication of root rot. Aloe vera flowers should have no detectable smell at all. Aloe vera gel will have a slight onion smell but will have a stronger bad smell when it goes off.
If your aloe vera plant has a mild onion or garlic smell then you have nothing to worry about. A slight onion-like odour is completely natural especially when you cut the leaves. Even the latex within the leaves, that is used mostly for skin care, will have a slight garlic smell.
If however, your aloe vera plant smells very bad then this is a sign that it has root rot and you must treat it as soon as possible or you will lose the plant. See the information in the section directly above this one for how to do that.
If it is the aloe latex (the gel within the leaves), which was previously harvested or that is in a store-bought product, starts to smell bad then the gel has gone off and you should dispose of it. If the latex gives off a very strong and unpleasant odour as soon as you cut the aloe leaf then this is a strong indication that the plant is suffering from root rot.
Read our article on aloe vera root rot and its treatment for detailed information about fixing this problem in all aloe plants.