What Are the Most Common Succulent Pests and Diseases and How to Treat Them?

You’ve noticed something’s off with your succulent, and you’re worried it might be a pest or disease. You’re not alone-this is a common hurdle for plant lovers, but the good news is most issues are treatable if you catch them early.

In this guide, I’ll walk you through exactly what to look for and the simple, effective treatments I’ve used for years. We’ll cover mealybugs, spider mites, scale, fungus gnats, root rot, and powdery mildew.

Meet the Unwanted Guests: Common Succulent Pests

Mealybugs: The Fluffy White Menace

You’ll spot these pests as tiny, cotton-like fluffs nestled in the crevices of your plant, especially where leaves meet the stem. I’ve found that the first sign is often a sticky residue, called honeydew, on the leaves or the surface below the plant. They suck the sap right out of your succulent, leaving it weak and stunted.

My go-to method is using a cotton swab dipped in isopropyl alcohol to dab each bug directly. For larger infestations, I mix one part 70% isopropyl alcohol with three parts water in a spray bottle and thoroughly mist the plant, getting into every nook.

• Isolate the infected plant immediately to prevent spreading.
• Check neighboring plants thoroughly for several weeks.
• For persistent cases, repot the plant in fresh, sterile soil.

Scale Insects: Stubborn Little Bumps

Scale insects are masters of disguise, looking like small, brown, tan, or white bumps stuck to the stems or undersides of leaves. They don’t look like they’re moving, which is why an infestation can get bad before you even notice it. Like mealybugs, they pierce the plant and feed on its juices.

Scraping them off gently with your fingernail or a soft toothbrush is effective for light cases. Follow up with the same alcohol spray treatment used for mealybugs to kill any crawlers you might have missed.

1. Physically remove as many scales as possible.
2. Wipe down the entire plant with an alcohol-soaked cloth.
3. Apply a horticultural oil or insecticidal soap, ensuring full coverage.

Spider Mites: Nearly Invisible Weavers

These pests are so tiny you might see their damage before you see them. Look for fine, silky webbing between leaves and a stippled, dusty appearance on the foliage. I once lost a favorite echeveria to these guys because I mistook the webbing for harmless dust. They thrive in hot, dry conditions, which many of us provide for our succulents.

A strong blast of water from a hose or spray bottle can dislodge a surprising number of them. For a more thorough approach, neem oil is my preferred treatment. I mix it according to the bottle instructions and spray the plant every few days until they’re gone.

• Increase humidity around the plant temporarily by misting.
• Wipe leaves with a damp cloth to remove mites and webbing.
• Neem oil treatments are most effective when applied in the cooler evening hours.

Fungus Gnats: The Annoying Airborne

If you see tiny, dark flies buzzing around your plant’s soil, you’ve got fungus gnats. The real problem isn’t the flies themselves, but their larvae, which live in the soil and munch on tender root hairs. This is a classic sign of overwatering, as they are attracted to consistently moist soil.

The simplest solution is to let your soil dry out completely between waterings. I also use yellow sticky traps inserted into the soil to catch the adult flies and break their life cycle.

1. Place yellow sticky traps near the soil surface.
2. Water with a mixture of one part 3% hydrogen peroxide to four parts water to kill larvae.
3. Add a half-inch layer of sand or gravel on top of the soil to prevent adults from laying eggs.

When Things Get Mushy: Common Succulent Diseases

Root Rot: The Silent Killer

This is the number one reason I’ve lost succulents over the years. Root rot happens when the soil stays wet for too long, suffocating the roots and allowing rot-causing fungi to take over. The first above-ground sign is often a plant that looks unwell, with leaves turning yellow, translucent, and mushy.

You must act fast. Gently remove the plant from its pot and shake off the soil. Inspect the roots-healthy ones are firm and white, while rotten roots are brown, black, and slimy. Use sterile scissors to cut away all the rotted parts.

• Let the plant’s roots air dry for a day or two before repotting.
• Always repot in a fresh, well-draining succulent mix.
• Ensure your pot has a drainage hole-this is non-negotiable.

Stem Rot: A Top-Down Problem

Stem rot often starts from the top, especially if water is allowed to sit in the rosette of a plant like an echeveria or sempervivum. You’ll notice the stem becoming soft, discolored, and almost squishy, sometimes with a foul smell. It can spread frighteningly fast.

If you catch it early, you can perform “surgery.” Using a clean, sharp knife, cut the plant well above the rotted section. Let the cutting callous over for a few days, then place it on dry soil to re-grow roots. The original base is often a lost cause.

Powdery Mildew: The Chalky Coating

This disease looks exactly as it sounds: a white or gray, powdery film on the leaves. It’s more common in conditions with poor air circulation and high humidity, which is why I’m careful about crowding my plants together. While not immediately fatal, it weakens the plant by blocking sunlight.

A simple home remedy is to mix one tablespoon of baking soda and half a teaspoon of liquid soap in a gallon of water. Spray it on the affected leaves thoroughly. For a stronger, ready-made option, I’ve had great success with a sulfur-based fungicide.

• Improve air flow around your plants by spacing them out.
• Avoid getting water on the leaves when you water.
• Remove severely infected leaves to prevent the spread of spores.

Your First-Aid Kit: Effective Treatment Plans

When you spot trouble on your succulents, don’t panic. I’ve found that a calm, methodical approach almost always saves the plant. Your first step is always to isolate the sick plant from your healthy ones to prevent any pests or fungi from throwing a party.

Physical and Organic Controls

I always start with the gentlest methods. These solutions are safe, effective, and you probably have the ingredients in your kitchen. This is my go-to strategy for early infestations before they get out of hand.

• The Rubbing Alcohol Swab: For mealybugs and scale, I dip a cotton swab in 70% isopropyl alcohol and dab it directly on the pests. You’ll see them dissolve on contact. It’s incredibly satisfying.
• Water Spray Blast: A strong jet of water can knock aphids and spider mites right off the leaves. I do this in my sink or shower, making sure to support the plant so it doesn’t get damaged.
• Neem Oil Solution: This is my organic powerhouse. I mix one teaspoon of neem oil and a few drops of mild dish soap into a quart of warm water, shake it well, and spray all plant surfaces every few days. It disrupts pests’ life cycles without harsh chemicals.
• Diatomaceous Earth: For pests crawling on the soil surface, I sprinkle a fine layer of this powder. It’s made from fossilized algae and feels soft to us, but it’s like walking on broken glass for tiny bugs.

Quick Tip: Always test any spray on a single leaf first and wait a day to ensure it doesn’t cause sunburn or damage.

When to Use Chemical Controls

I reserve chemical pesticides as an absolute last resort. You should only bring out the big guns when a severe infestation is actively killing your plant and gentler methods have failed. Systemic insecticides, which the plant absorbs, can be effective for stubborn pests like mealybugs that hide in soil roots.

If you must use them, I apply them outdoors or in a very well-ventilated area, always wearing gloves and following the label instructions to the letter. My personal rule is to never use systemics on edible plants or on any plant that will live indoors long-term.

Step-by-Step: Saving a Rotting Succulent

Root or stem rot is the most common killer of succulents, usually from overwatering. I’ve performed this “surgery” dozens of times, and it has a high success rate if you act fast.

1. Unpot and Inspect: Gently remove the plant from its pot. Brush away the soil to get a clear look at the roots and stem base.
2. Sterilize Your Tools: Wipe your pruning shears or a sharp knife with rubbing alcohol. This prevents spreading the rot-causing bacteria.
3. Cut Away All Rot: This is the hard part. You must cut away every soft, mushy, or blackened part of the stem and roots. Healthy tissue is firm and may be white, green, or tan. Cut well above the rotted area until you see only clean, healthy flesh.
4. Let it Callus: Place the cuttings or beheaded plant in a shady, dry spot for several days to a week. The cut end must form a dry, hard scab (a callus) before you even think about replanting.
5. Replant in Fresh Soil: Once callused, plant your succulent in a pot with a drainage hole, using completely fresh, dry, well-draining succulent mix. Do not water it for at least a week to encourage new root growth.

Seeing new, firm growth from the center of the plant is the best sign that your rescue mission was a success.

Prevention is the Best Medicine: Proactive Plant Care

In my years of collecting succulents, I’ve found that stopping a problem before it starts is far easier than fighting a full-blown infestation. A healthy succulent is naturally more resistant to pests and diseases, so your primary goal is to build that resilience from the start.

Master Your Watering Routine

Overwatering is the single biggest mistake I see new plant parents make. It’s not about a strict schedule; it’s about responding to your plant’s needs.

• Soak and Dry Method: I always wait until the soil is completely dry all the way to the bottom of the pot before I water again. I stick my finger or a wooden chopstick deep into the soil to check.
• Water the Soil, Not the Plant: Pour water directly onto the soil, avoiding the leaves and the center rosette. Trapped water invites rot and fungal issues.
• Seasonal Shifts: In the winter, when my succulents are dormant, they might only need water once a month or even less. I pay close attention to signs of thirst, like slightly wrinkled leaves.

When in doubt, wait another day or two to water-succulents are built to handle drought far better than flood.

Quarantine and Inspection

Every time I bring a new plant home from the nursery, it goes into a two-week timeout. I learned this the hard way after a mealybug outbreak spread to half my collection!

1. Isolate the new plant in a separate room, away from your other plants.
2. Examine it thoroughly under bright light. Look under leaves, along stems, and in the tight crevices where pests love to hide.
3. Wipe the leaves with a soft, damp cloth to remove any dust or unseen hitchhikers.

This simple quarantine habit has saved me countless hours of pest control down the line. It gives you time to spot any issues before they become a household problem.

Create a Healthy Environment

Think of your succulent’s environment as its immune system. The right light and airflow make it a fortress against problems.

• Bright, Indirect Light is Key: My succulents thrive in a south or east-facing window where they get plenty of bright, but not scorching, light. Weak, stretched-out plants are easy targets for pests.
• Promote Good Airflow: Stagnant, humid air is a breeding ground for fungus. I use a small oscillating fan on a low setting in my plant room to keep the air moving gently.
• Use a Gritty, Well-Draining Soil: I mix my own potting soil with plenty of perlite and coarse sand. This ensures water flows through quickly, preventing the roots from sitting in moisture.

If your home is dark, consider a simple grow light-it makes a world of difference for keeping plants compact and strong. A happy plant in the right spot will naturally fight off most minor issues on its own.

Common Questions

What are the first signs my succulent has a pest problem?

Look for sticky residue, cotton-like fluffs, small bumps on stems, fine webbing, or a general dusty appearance on the leaves.

How can I identify succulent pests and diseases from pictures?

Comparing pictures of common issues like mealybugs, scale, and powdery mildew to your plant’s symptoms can help with accurate identification.

Are there any pests specific to succulents in Australia?

While common pests like mealybugs and scale are widespread, Australia’s warm climate can also attract ants that farm sap-sucking insects on your succulents.

What is the most common disease that kills succulents?

Root rot, caused by overwatering and poorly draining soil, is the most frequent and fatal disease for succulents.

Can a succulent recover from a severe pest infestation?

Yes, with immediate isolation, persistent treatment like neem oil or isopropyl alcohol, and repotting in fresh soil, a succulent can often fully recover.

What is the single best way to prevent succulent pests and diseases?

Providing proper care with well-draining soil, bright light, good airflow, and correct watering is the most effective preventative measure.

Your Succulent Care Journey

In my years of nurturing succulents, I’ve learned that staying proactive with simple, consistent habits is your best shield against pests and diseases. Catching issues early and using gentle, targeted treatments will keep your plants resilient and vibrant. Focus on these core practices:

• Check plants weekly for unusual spots or insects.
• Treat infestations with natural options like rubbing alcohol or insecticidal soap.
• Adjust watering and light to prevent root rot and fungal problems.

For ongoing support, follow along with us at Hardy House Plants where I share more hands-on tips from my own plant adventures. Don’t worry-with a little patience and care, you can confidently handle any succulent challenge that comes your way.

Further Reading & Sources

• Succulent Pests & Diseases: Identification and Effective Treatment – Succulents Box
• Succulent Plant Pests, Diseases, Problems: Symptoms & Solutions
• 14 Succulent Pests And Diseases Along With Simple Tips To Fix The Problems
• Succulent Pests & Diseases – Leaf & Clay