All About Succulent Diseases and Pests

Most succulents are dry climate plants that dislike humidity and frequent watering. Excess moisture can cause many issues, including powdery mildew. This common succulent disease resembles a fine white powder on the leaves.

While mildew and fungus issues don’t normally kill succulents, they can cause major damage. Use neem oil or a mixture of dish soap and water to clean your succulents. You should also remove powdery mildew-covered leaves as soon as possible and consider replanting if the soil is too waterlogged.

Bacterial soft rots cause more crop loss around the world than any other bacterial disease, and they can ruin your succulents, too. At first, the spots resemble water-soaked areas. Over time, the leaves of your succulents become soft, wrinkled, and discolored. Soft rot has no cure, so you must dispose of the plant.

This sounds like an overwatering problem, but in fact, underwatering may cause issues that resemble soft rot, as well. Look for a signature foul, rotting smell to identify bacterial soft rot.

Mealybugs are infamous for their ability to destroy otherwise healthy succulents. These pests resemble tiny pieces of fluff and are often visible along the stems. Mealybugs are quick eaters, rapidly moving from plant to plant, and they leave behind a honeydew-like secretion that encourages mold growth.

Eliminating mealybugs requires vigilance and patience. Start by quarantining the affected plants. Remove your succulent from the pot and rinse it. Toss out the old soil and scrub the pot with hot, soapy water. Allow the plant to dry out, then replant it with fresh soil. Mix rubbing alcohol or neem oil with dish soap and spray the infected plant. Repeat this process several times over the next few days until you no longer see mealybugs. Continue spraying the succulent once a week until mealybugs no longer reappear.

Aphids are common garden pests that love to munch on a variety of plants, including succulents. Like mealybugs, these tiny yellow, green, or black creatures feed on plant sap and release a substance that may encourage mold development.

Thankfully, aphid infestations are among the easiest to manage. Simply wash your succulents with a strong stream of water or brush them with an alcohol-soaked cotton swab.

Another common garden nuisance, scale insects are teeny tiny pests that consume plant sap, secrete a sticky substance, and spread viral diseases. They can multiply very quickly and may devastate an entire collection of plants.

Look for these pinhead-sized insects on the underside of leaves and other shady areas. Like aphids, you can fight scale infestations by washing your plants and using cotton swabs with rubbing alcohol.

Among the smallest enemies of your succulents, red spider mites are nearly microscopic. To the naked eye, they look like nothing more than some dust particles. You’ll most likely notice them after they multiply and cover your plant in webbing. Affected succulents often grow yellow or brown spots and become much more vulnerable to disease.

Red spider mites hate moisture and a good washing will eliminate most colonies. If you want to use a pesticide, make sure to use a specific miticide; general insecticides may not be effective.

Any outdoor succulent or cactus is at risk of becoming the victim of a snail infestation. You can often find snails resting on the side of your pots and containers or under the leaves of larger succulents. Despite their size, snails can ingest significant amounts of plant tissue.

Remove individual snails by hand, making sure to check under pots and near any shady areas. Major snail and slug colonies may require snail bait and specific pesticides. If you live in a warm, humid region, you may need to take regular steps to eliminate these slimy pests.

All succulent owners should be ready to face fungus gnats. These insects look similar to fruit flies and often target young succulents. In autumn, fungus gnats lay their eggs in nutrient-rich soil. As the larvae hatch, they eat roots and may spread to the entire plant.

Because fungus gnats can be difficult to notice until it's too late, your best bet is prevention. Keep humidity levels low and use pumice to drain excess moisture from the soil. Some experts also swear by using a small amount of powdered cinnamon to keep gnats at bay. While the diagnosis may be late, you can eliminate fungus gnat infestations with larvicides.

Ants love to nest in the soil beneath gasteria, aloe, and haworthia, munching on their cores. Additionally, the honeydew that other pests produce may attract ants, who will then attack your succulents.

To correct the problem, peel away damaged leaves until you only have unblemished leaves and the core. Wash the roots and replant the affected succulent in fresh soil, preferably in an area where ants cannot easily reach it. A common solution is to place the pot on an elevated stand with a small moat of water.

Leafy succulents are particularly prone to attacks from whiteflies. These white flying insects can be difficult to notice and control. Shake the leaves of your succulents and look out for any flying pests.

Blast the tiny insects off with water, or use diluted dish soap. Horticulturists recommend hanging trap crops like fuchsia near doors to attract pests and keep your succulents safe.