Last Updated on March 20, 2023 by Cristina
Aloes are one of my favorite plant types. They are tough, beautiful, and largely maintenance-free. One or two little things can go wrong with them if they are a bit unhappy. Why does my aloe plant have white spots is a rather common question with a number of answers. Let’s have a look at a few aloes with white spots and figure out what we can do about them.
What Are Aloes?
The Aloe genus comprises over 560 species of succulent plants that all have a very characteristic growth pattern. The leaves grow in a rosette-type twirl generally, and the plants employ CAM photosynthesis. The link I shared is one of the best explanations of CAM photosynthesis I have ever seen – I wish I had access to that when I did Botany 101!!
Aloes are indigenous to parts of Africa, the Arabian Peninsula, and as far north as Jordan, as well as Madagascar and some of the little Indian Ocean Islands. Most of us have heard of Aloe vera, but there are 559 other species at least to be interested in too! All of these can get white spots on their leaves for various reasons.
White Spots Caused By Aloe Scale/Aphids/Mealy Bugs
Aloe Scale
Why does my aloe plant have white spots? The most common cause I know is the aloe scale. This irritating pest seems to just appear out of thin air and then it infests a leaf, or a few leaves for a while. After a few years, or decades these infestations can suddenly vanish. In certain cases, they can kill the plant.
They are relatively easy to remove – I just use a few of these alcohol swabs to wipe the scale off. You need to press quite hard, and the scale just wipes off. Don’t squash the leaves. After you wipe the leaves off, rinse the plant with a hosepipe spray gun. The scale tends to come back so you can do a follow-up spray every two or so weeks with a bit of neem oil spray. This inhibits their return and allows your aloe to become healthy again. Once it is healthy, it should be able to defend itself against the aloe scale.
Plants that have been overwatered, or are a bit nutrient-starved tend to get this scale. When they are healthy they do not get it.
This Aloidendron barberii (cursed taxonomists have renamed this thing again) has had a scale infestation on just one of its many heads for nearly twenty years. The plant seems to be ok and survives. I have seen other aloes succumb to the scale, but in this case, I think they had other underlying health conditions that caused this to happen.
Aphids and Mealy Bugs
Learn more about: How To Get Rid Of Aphids- Best Natural Methods
These tend to be ant-associated pests. Ants farm these on aloe leaves and harvest sap from them. I often find I will get a little aphid/mealy bug infestation on an aloe – this is typically accompanied by an ant colony that has moved in at the base of the aloe. These little black ants farm the aphids. After a few weeks, a lizard or gecko will move in, eat most of the ants, and within a few more weeks the infestation goes away. Sometimes this does not happen and then I just spray them with a bit of neem oil.
You can place a follow-up bait station to kill any ants that may return. These bait stations have a slow-killing poison of some sort that goes back to the queen and removes her. This helps a bit.
I am becoming increasingly fond of entomopathogenic fungi for the biological control of aphids and other pests. There are a few interesting formulations on the market now such as this one. I have not tried this one on any aloe problems, but have used it to control a range of other common garden pests this year with great effect. A large legal cannabis cultivation facility where we are doing some work also uses a range of these controls with high levels of efficacy.
White Spots Caused By Snout Beetles
Why does my aloe plant have white spots on the leaves and a dead growth shoot? This is normally caused by snout beetles or aloe beetles. This beetle seems to be more likely to cause trouble to weak plants – strong plants do not get killed by it, but they do get disfigured. The circular spots on the leaves look ugly, and sometimes the whole growth crown can die, or sort of retreat back into the plant for a while and then resurrect, but the plant looks a bit mangled after this.
I love Aloe arborescens and have planted over a hundred of these plants on both sides of the road outside my house. In bad years the snout beetle will kill some growth shoots – in good years such as this year, it just makes a few irritating marks on the leaves and can sometimes stop the aloe flowering. It is quite clear that when asking “Why does my aloe plant have white spots?” the snout beetle is a prime suspect.
For a nice guide on how to treat aloe snout beetles read here.
White Spots That Are Supposed To Be There
Sometimes the answer to the question “Why does my aloe plant have white spots?” is because your aloe actually does have white/yellow spots. Variegated aloes are not uncommon and some can develop these spots more vividly and less vividly depending on season and growth conditions.
This aloe growing near my house has a natural “white spot on the leaf” that is part of how it looks. When the plant is a bit dry, the leaves go red and the white spots stand out a lot more. When they are wetter and flourishing, the white spots go light green and the rest of the leaf goes dark green. Under these conditions, the variegation is less discernable.
I hope this has helped you answer your question “Why does my aloe plant have white spots?” and led you to a course of action to either treat or accept the spots! If you found this helpful please share.
FAQs
How do I get rid of white spots on my aloe plant?
Identify if they are variegation (these are natural and will not go), aloe scale (white bumps that wipe off with alcohol wipes), mealy bugs or aphids (normally there are ants present too - use neem oil and ant traps) or aloe snout beetles (systemic insecticides as horrible as they are can help).
What does an overwatered aloe plant look like?
An overwatered aloe shows signs of stress - the leaves go a reddish yellow colour and get a bit soggy, and can develop brown spots. The alow will wiggle at its base a bit as the roots rot. It is best to repot an over watered aloe in fresh dry succulent soil. It should recover.
What does an unhealthy aloe plant look like?
When an aloe plant is unhealthy it normally goes a red color and the leaves get squishy. Aloes are really tough - if they get this red color it is most often due to either too much or too little water. They also need enough light, but normally if they don't have enough light they will start to stretch toward the light. The most common aloe problems tend to be related to under or over watering. If the soil is dry and the aloe is a reddish soggy texture, water it. If the aloe is wet and the soil is soggy, and it has similar symptoms, let the soil dry out. Aloes are really difficult to kill.
How do you bring aloe vera back to life?
This will depend on what has caused it to become unhealthy. My first step with any succulent is to repot it in fresh good well drained succulent soil. A bigger pot always helps, and then wipe its leaves clean with alcohol wipes to remove any pests, spray it with neem oil spray and replant it. Place it on a windowsill where it gets warm day sunlight and cool, but not freezing nights. If you can kill an aloe you have special skills! These things are tough.
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