Everything You Need to Know About White Spots on Succulents

Are white spots on succulents normal?

Back when we were kids, my sister and I performed the great cactus heist. We plucked a plantlet off this beautiful succulent being sold at the supermarket, wrapped it in tissue, and brought it home.

Not long after we grew it in a pot, we started seeing white spots in the leaves. They would appear and prevent the plant from growing any further. And they didn’t look nice!

After I did some digging, I found out that these white spots either appear because of mealybugs, mildew, sunburn, edema, or for completely different reasons. Some of those reasons are actually normal and not worth worrying over.

Here, I’ll let you in on what I found out, and how to solve the issue and save the plant.

Natural White Spots on Succulents

Before you start worrying, you should first identify whether the white spots are a natural occurrence.

Succulents like aloe vera, hawthorias, and astrophytums all have natural white spots. Meanwhile, some succulents like echeverias, dudleya pulveruleta, and silver crown have what appears to be fine white powder coating.

As cacti and succulents grow in very sunny areas, some of them eventually develop natural white markings to help them tolerate the harsh rays.

You probably know that the color white reflects light, so these white spots are the plant’s way of protecting itself from sunburn.

It’s good to be able to differentiate the white spots that are naturally present on your succulents from those that are harmful. This way, you may be able to spot when your plants develop more concerning white spots.

Non-Harmful White Spots on Succulents

White Spots on Succulents

Some white spots aren’t natural, but they aren’t harmful either.

Some succulent owners will often notice white round rings forming on their plants. These are mineral deposits caused by using hard water for watering the plant. Salt and minerals naturally occur in water, and they can dry up some parts of your plant and cause white spots.

This issue is very minor and doesn’t affect the plant’s growth. To remove these white spots, you can wipe them away with a soft damp cloth. Use distilled water if possible.

Prevent these white spots from appearing again by avoiding splashing the cacti stems while watering.

Potentially Harmful White Spots on Succulents

There are plenty of other more concerning reasons for your succulents to have white spots. These could be due to the environment or due to the presence of pests and diseases.

If you want to keep your succulent healthy, you’ll want to know the signs you should look out for, so you should start treatment as fast as you can.

Here are the possibly harmful causes of white spots on your succulents:

Spine Mealybugs and Root Mealybugs

Pseudococcus mealybug infestation on green plant

Mealybugs are a serious issue in succulents. Spine and root mealy bugs are often found on cacti that have dense spines where the bugs can easily hide. You can identify them by the yellowish color they give when you crush them with your fingers.

Mealybug pupae produce a white, fluffy substance that sticks to the stems and roots of succulents. This sort of infestation can severely affect your plant and stunt its growth.

At the first sign of mealybugs, immediately isolate the plant and remove all severely infested leaves and stems. For smaller infestations, you can rub the white substance off with methylated spirits and a cotton swab.

After removing the fluffy substance, quickly spray the affected areas with an insecticidal spray. Make sure to wear a face mask when doing this to avoid irritating your lungs.

It’s also possible to use an alternative and natural insecticide like neem oil. However, please note that neem oil can irritate sensitive skin. It’s better to use gloves when handling it.

It’s also worth noting that neem oil may not be effective on velvety and fuzzy types of succulents as there are more places for the mealybugs to take cover. That being said, it’s a decent alternative to harsh artificial insecticides.

Users Also Read: Succulent Propagation Timeline and Brief Guide for Beginners

Cochineal Scale

Cochineal scales are another type of pests that can be found on succulents. They’re most common on prickly pears and paddle cacti. Cochineal scales are small parasites that appear as white and cottony spots.

The white portion of the cochineal scale acts as the insect’s armor. When crushed, a red substance composed of mostly carminic acid is found inside. Interestingly, this substance was used as a dye for fabrics by the Aztecs and as a natural food coloring since the 18th century.

Cochineal scale insects are dangerous to succulents as they latch onto the plant and consume its tissues.

For severe cases, slice off the affected areas at the joints. Then, spray the scales off with a strong jet of water to dislodge the pests. You can also spray the plants with neem oil solution and scrub the pests off with a clean toothbrush. Do this every six weeks or as needed until the infestation disappears.

Mildew Infection

Remember our (me and my sister) succulent that I mentioned earlier? The white spots on it turned out to be a mildew infection. Yikes!

Mildew infection occurs when succulents are exposed to damp climates or as a result of overwatering. When your succulent’s soil retains water, it eventually leads to root rot. That’s why well-retaining soil is essential for a succulent’s health.

Mildew infection appears as powdery circular spots on the cacti. It can be treated with a mildew spray. However, if it’s caused by the climate, there is little you can do. The symptoms will likely not completely go away.

Edema

Succulent with edema

Edema happens when there is abnormal water retention in plants, and it often happens as a reaction to changing environments.

Distorted white spots appear along the lower portion of the leaves. This happens when the succulent is growing in cold conditions and then is suddenly brought to intensely hot environments.

Edema can also be caused by stress resulting from inconsistent watering. This commonly happens to agave plants.

To treat edema, make sure that your succulents aren’t sitting in water. There must be proper drainage, so make sure that your soil is well-draining and that the drainage holes on the pot are working.

Slowly increasing the plant’s exposure to light over a week may also help prevent edema. The most important thing is to avoid sudden changes to the temperature surrounding the plant.

Sunburn

Who would have known that plants can get sunburned? Succulents, especially newly cut ones that have not been able to develop roots, can get sunburned. Sunburn can happen when the plant has been living indoors with minimal sunlight, and then it’s suddenly exposed to direct sunlight without the chance to adapt.

The sunburn appears as minute white dots on the plant. It’s a minor issue and usually, the succulent can recover from it. However, you may prevent sunburn from happening by simply protecting your plants from the harsh sunlight and by exposing them to light gradually. It’s better than dealing with the consequences.

Also Check: Your Complete Guide to Sacred Succulents

 Final Thoughts

Some of the causes of white spots can be minor and easily treatable. However, some white spots on succulents can become deadly if left for long without treatment. For this reason, you need to be aware and act quickly at the first sign of them.

Be it pests, disease, or just a physical reaction to the environment, you should know that your succulents can recover with the proper treatment and care.

As long as you can identify the cause, what comes next is—hopefully!—easy.