Common Succulent Pests and How to Eliminate Them
If your succulent has cottony white fuzz in the leaf joints, sticky spots on the leaves, or gnats hovering over the pot, you're dealing with one of a handful of common succulent pests and how to eliminate them comes down to identifying which one it is. These problems are almost always tied to how the plant is watered and housed, not bad luck. Most of these problems start with soil that stays wet too long. Fix the watering and the pest usually stops coming back after treatment. Below is what each pest actually looks like, what kills it, and what doesn't work no matter how many blog posts recommend it.
Mealybugs
What you'll see
Small white cottony tufts wedged into leaf joints, along stem nodes, or tucked under the bottom leaves where you can't see them without tilting the pot. They leave behind a clear sticky residue (honeydew) that can turn black with sooty mold if it sits for weeks.
What actually works
- Cotton swab + 70% isopropyl alcohol. Dab each visible cluster directly and wipe it away rather than just smearing it around; the alcohol dissolves the waxy coating that protects them. UC Statewide IPM Program recommends this exact approach for small infestations and warns that alcohol above 70% can scorch tender leaves, so test one leaf first and wait a day before treating the whole plant.
- Isolate the plant. Mealybugs walk from pot to pot and hide in the crevices where pots touch. Move an infested succulent away from the rest of your collection until you've had zero sightings for a few weeks.
- Repeat weekly. Alcohol kills adults and nymphs on contact but does nothing to eggs tucked deeper in the joints, so one treatment is never enough. Expect several rounds, roughly a week apart, until you see no new activity.
- Insecticidal soap or neem oil as a backup for large plants where swabbing every bug isn't realistic. It smothers young nymphs better than adults, so pair it with manual removal for anything visible.
What doesn't work: spraying water alone. Mealybugs are protected by a waxy coating that sheds water, so a hose blast just knocks the visible ones onto the soil, where they climb back on.
Aphids
What you'll see
Small green, black, or yellow soft-bodied insects clustered on new growth and flower buds, plus curled leaves and ants patrolling the plant (ants farm aphids for their honeydew, so ants are often the first clue).
What actually works
- A strong jet of water first, aimed at the clusters. Aphids have soft bodies and no strong grip, so this physically knocks most of them off and is often enough on its own for a light infestation.
- Insecticidal soap for anything that survives the water spray, reapplied every 5-7 days for two to three rounds.
- Neem oil as a foliar spray in the evening (never in direct sun, which can burn treated leaves) if soap alone isn't keeping up.
Scale Insects
What you'll see
Small oval or round bumps, brown or tan, stuck flat against stems and leaf undersides. Unlike mealybugs, scale doesn't look like an insect at all at first glance; it looks like a texture defect on the plant.
What actually works
- Scrape them off with a fingernail or an old toothbrush. The waxy shell protects them from sprays, so physical removal is the most reliable first step.
- Follow with rubbing alcohol on a cotton swab to kill any nymphs (called crawlers) you can't see yet, since these are the mobile stage that spreads scale to new leaves.
- Horticultural oil for stems with heavy coverage, which smothers crawlers you'd otherwise miss.
Spider Mites
What you'll see
Fine webbing in leaf axils, tiny pale speckling on leaf surfaces, and a dry, dusty look to the plant. You often won't see the mites themselves without a hand lens; the webbing is the giveaway.
What actually works
- Water spray to physically dislodge mites and destroy webbing, repeated every few days.
- Increase humidity around the plant (not the soil) since spider mites thrive in hot, dry air; a pebble tray or grouping plants together helps.
- Miticide only for infestations that don't respond to water and humidity after two or three weeks; most home growers never need this step.
Fungus Gnats
What you'll see
Small dark flies hovering near the soil surface, especially when you water. This one is almost always a watering problem, not a pest problem: the larvae live in the top layer of consistently damp soil and feed on organic matter and fine roots.
What actually works
- Let the soil dry out completely between waterings. Succulents should go through a full wet-to-dry cycle, watered thoroughly and then left alone until the soil is dry through the pot, which is also the single best way to prevent root rot in the first place, according to Iowa State University Extension. Check with a wooden chopstick or bare finger pushed an inch or two into the soil; if it comes out with damp soil clinging to it, wait.
- Repot into gritty, fast-draining mix if the current soil holds water for more than a few days after watering. A mix built for cactus and succulents (mineral grit, coarse sand, or pumice blended with a small amount of potting soil) dries fast enough that gnat larvae can't establish.
- Yellow sticky traps to catch adults and break the breeding cycle while the soil dries out.
- A thin layer of sand or fine gravel on the soil surface makes it harder for adults to lay eggs in the first place.
Whiteflies
What you'll see
Tiny white moth-like insects that scatter in a cloud when you disturb the plant, plus yellowing leaves and honeydew that can turn into black sooty mold.
What actually works
- Yellow sticky traps placed just above the plant canopy to catch adults, since they're drawn to yellow.
- Insecticidal soap or neem oil, applied to the undersides of leaves where whiteflies lay eggs, repeated weekly for at least three rounds since eggs hatch on a staggered schedule.
- A handheld vacuum on a cool, low setting run over the plant in early morning when whiteflies are sluggish; this physically removes a large share of the adult population in one pass.
Thrips
What you'll see
Silvery or bronze streaking on leaves, distorted new growth, and small black flecks of frass (thrips droppings) on the leaf surface.
What actually works
- Blue sticky traps (thrips are more attracted to blue than yellow) placed near affected plants.
- Neem oil applied weekly, focusing on new growth where thrips concentrate.
- Isolate affected plants, since thrips move easily between neighboring pots and spread fast in a crowded collection.
Why Most of This Traces Back to Watering
Fungus gnats need moist soil to breed. Mealybugs and scale spread fastest on stressed, overwatered plants with soft, weakened tissue. The single change that prevents the most repeat infestations is the same one that prevents root rot: water thoroughly, then let the soil dry out completely before watering again, in soil gritty enough to actually drain. Iowa State Extension calls this wet-then-completely-dry cycle the best way to avoid root rot in succulents, and it happens to starve out fungus gnat larvae and reduce the soft, waterlogged growth that soft-bodied pests prefer. Pair that with bright light; succulents kept too dim get thin, stretched growth that's more attractive to pests and less able to recover from an infestation.
A Note on Handling Aloe and Agave
Aloe and agave deserve a specific mention because people handle them barehanded more than other succulents, usually to harvest aloe gel or divide agave pups. Agave sap can irritate skin on contact, and the plant's sharp leaf-tip spines can cause a puncture wound that gets more painful than you'd expect from a houseplant. Wear gloves and long sleeves when working with either one, especially when cutting into agave leaves or trimming aloe.
Both plants are also a real risk to pets. The ASPCA lists true aloe (Aloe vera) as toxic to both dogs and cats, with vomiting and reddish urine as the reported signs of ingestion; the toxic compounds are aloin and related anthraquinone glycosides concentrated in the sap layer just under the rind, not the clear inner gel. If you suspect a pet has eaten aloe or agave, contact your veterinarian or the ASPCA Animal Poison Control Center rather than waiting to see what happens.
Prevention
- Water on a dry-soil trigger, not a schedule. Check the soil before you water; don't water on a fixed weekly habit regardless of how the pot feels.
- Quarantine new plants for two to three weeks before placing them near the rest of your collection. Most infestations start with one new plant from a nursery or big-box store.
- Inspect leaf joints and undersides monthly. Mealybugs and scale hide in the spots you don't look at casually.
- Space plants so leaves aren't touching. Crowded succulents trap humidity around the foliage and give pests a bridge from one plant to the next.
- Wipe down tools and pots between plants if you've had an infestation, since alcohol and scale crawlers can hitch a ride on a trowel or pruning snip.
FAQ
Can I just cut off an infested leaf or stem?
Yes, and for a small, isolated infestation it's often the fastest fix. Remove and discard the affected leaf or stem, then still check the rest of the plant weekly for a few weeks since mealybugs and scale crawlers may have already moved on before you noticed.
Is neem oil safe to use on succulents?
Generally yes, but succulents can be more sensitive to leaf burn than thicker-leaved houseplants. Apply in the evening or on an overcast day, never in direct sun, and test on one leaf first.
Why do the same pests keep coming back after I treat them?
Almost always one of two reasons: eggs survived the first treatment and hatched a week or two later, or the underlying condition (overwatering, poor drainage, low light, overcrowding) never changed, so the plant stayed vulnerable. Treat on a repeat schedule and fix the growing conditions at the same time.