The agave snout-nosed weevil is a major pest in ever-increasing numbers. Dont wait for signs of infestation; take preventative measures NOW to protect your agaves, furcraeas, yuccas, beaucarneas and mangaves. Please dont let your yard become a breeding ground for pests that move on to your neighbors!
ON THIS PAGE youll find photos of common succulent pests, diseases and problems; and discover causes, severity, prevention and treatments.
NOT SEEING WHAT YOU NEED? Describe your plants problem in a comment on the Pest and Diseases Forum.
Aeoniums are a popular type of succulent known for their striking rosette shapes and ease of care. However, like all plants, aeoniums can fall victim to diseases that impact their health and appearance As an aeonium grower, it’s important to be able to identify and treat common aeonium diseases so your plants can thrive In this article, we’ll cover the most common aeonium diseases, how to spot them, and effective treatment methods.
The Most Common Aeonium Diseases
Here are some of the most frequently seen diseases in aeonium plants
Powdery Mildew
Powdery mildew is one of the most prevalent fungal diseases in aeoniums. It appears as white powdery spots on the leaves and stems. Powdery mildew thrives in humid environments with poor air circulation. If left untreated, it can weaken and kill plants.
Root Rot
Root rot is a fungal infection triggered by overwatering. It causes the roots to turn brown and mushy. Plants suffering from root rot often appear wilted and fail to thrive. Root rot can spread quickly and can be fatal to aeoniums if left unchecked.
Stem and Crown Rot
Stem and crown rot is a fungal disease that attacks the main stem and crown of aeonium plants Infected plants appear stunted and collapse, This disease thrives in wet conditions and can kill plants rapidly
Leaf Spot
Leaf spot can be caused by either a fungus or bacterium. It appears as spots or lesions on leaves, which often spread until the leaves turn yellow and fall off. Leaf spot thrives in wet, humid conditions.
Identifying Aeonium Diseases
Catching diseases early allows the best chance of saving infected aeoniums. Here are the most common symptoms of sick aeoniums:
- Discolored or yellowing leaves
- Wilting or drooping
- White powdery coating on leaves
- Brown spots or lesions on leaves
- Stunted growth
- Mushy or rotting roots or crown
- Presence of pests like mealybugs or aphids
Inspect plants frequently looking for any of these signs of trouble. Check both the leaves and roots for indications of disease. Catching issues early makes treatment more likely to succeed.
Treating Aeonium Diseases
Once you’ve identified an aeonium disease, prompt treatment can help restore health. Here are some effective treatment methods:
Powdery Mildew Treatment
- Prune off affected parts of the plant
- Apply neem oil or a sulfur-based fungicide as directed
- Improve air circulation around plants
- Reduce watering and avoid wetting leaves
- Apply baking soda spray weekly to deter recurrence
Root Rot Treatment
- Remove plant from pot and cut away all rotten roots
- Repot in fresh, sterile potting mix
- Allow plant to dry out between waterings
- Apply a fungicide drench to kill remaining root rot fungus
Stem and Crown Rot Treatment
- Remove entire infected plant including all roots and soil
- Sterilize the pot before replanting
- Water new plants sparingly and avoid crown wetness
- Apply fungicide powder around base of the plant
Leaf Spot Treatment
- Prune off all spotted leaves
- Apply copper-based fungicide spray
- Improve air circulation around plants
- Water plants at the base, avoiding wetting leaves
- Remove any fallen leaves promptly
Preventing Aeonium Diseases
Prevention is the best medicine when it comes to aeonium plant health. Here are some key tips for avoiding diseases:
- Provide good air circulation between plants
- Allow soil to dry between waterings
- Water at the base, avoiding contact with leaves and crown
- Sterilize pots and tools regularly
- Inspect new plants closely before introducing to your collection
- Isolate plants at the first sign of disease
- Remove fallen leaves promptly
- Avoid overhead watering
- Use well-draining soil and pots with drainage holes
- Maintain proper humidity levels – not too high or low
Quick action at the first sign of disease gives you the best chance of saving your aeoniums. Familiarize yourself with the most common diseases so you can readily identify them. Have a treatment plan in place and be prepared to isolate and treat plants as soon as issues arise. With proper care and prompt treatment, your aeonium collection can remain lush and beautiful for years to come.
Color change (reversion to green)
- Normal if plant is otherwise healthy
Certain succulents—notably crassulas (jades) and aloes—blush red or orange when environmentally stressed, that is, given more sun and less rich soil and water than ideal for optimal growth. Nurseries are pros at producing colorful, healthy succulents because they sell better than plain green ones. When you bring a red, orange, yellow or purple succulent home, give it the same amount of sun, lest it revert to green. Solid green succulents do tend to be more vigorous. To stress a green succulent, increase exposure gradually for a week or so, lest it sunburn.
This indicates mycoplasma infection. The bacteria enters the plants roots and then its leaves from soil that contains horse manure. Your source nursery needs to know theyre selling diseased plants (ask for a refund). Once in a plants tissues, the only treatment is Agri-mycin, a pricey horticultural antibiotic. My recommendation is to bag the plant and put it in the trash, soil and all. Clean the pot thoroughly before reusing. Learn more in the Disease section of my video: Dick Wright on How to Grow Echeverias. Fast forward to 6:06.
- Normal, if center growth is healthy
New leaves form at the center of a succulents rosette or from the tip of its stem. Older lower leaves wither and die, and may persist on the stem, thereby shading it from harsh sun and insulating it from cold.
Certain succulents, notably dudleyas, close their rosettes during their summer dormancy to protect their vital cores, so all you see are dead leaves. It’s generally better for the plant if you leave them on, because they do have a purpose, but if you find them unsightly, peel them away. Also check to see if they harbor pests such as mealy bugs.
Large bites taken out of leaves as well as uprooted plants are indicative of deer. At first sign of damage, apply a deer repellent. If the situation becomes intolerable, the only recourse may be to plant deer-resistent plants or surround your garden with 7-foot fencing.
- Normal
- May be fatal if unremedied
When formerly plump leaves become wrinkled and lose their sheen, its a sign that theyre drying out. During times of drought in their native habitats, succulents live off the moisture in their leaves, so they can survive a lack of water that would kill other plants. So long as the succulents vital core is healthy and hasnt been compromised by pests that prey on weakened plants, it will recover when watered or the rains return.
- Normal for certain kinds of succulents, mainly agaves
Succulents that are “monocarpic” die after they bloom. Aeoniums, sempervivums, and agaves are best-known for being monocarpic, but some (like A. americana) take 15+ years to flower—hence the name “century plant.” Less common monocarpic succulents include furcraeas and orostachys. Paddle plants (Kalanchoe luciae) do bloom themselves nearly to death, but unlike true monocarps, plants can be saved if you cut the flower stalk as it forms.
Read my post “Big Blues Life and Demise” about my own Agave americana and see its removal on my YouTube channel: “Agave americana Bloom and Removal” (4:44).
Also on my channel:“What You MUST know about Century Plants” (2:50).
Succulents tend to grow in the direction of greatest sun exposure. Leaves and stems that appear stretched or leaning are “etiolated,” a term that means growth that results from inadequate light. Etiolated rosette succulents will stretch, lean and flatten their leaves to expose more of their surface to the sun.
Provide the plant with more light (gradually, lest it sunburn) and rotate potted succulents and wreaths for even light exposure and to avoid lopsided growth.
Over time, as a succulents oldest leaves wither, die and fall (or are trimmed) off, branches and stems can become denuded. Snip healthy tip growth and replant as cuttings. If you cut above healthy leaves, the stem may branch, creating a fuller plant. In the photo, a single plant has the potential to yield 50 cuttings. Theres no point in keeping a leggy, leafless succulent, so after harvesting cuttings, discard it roots and all.
See my videos How to Redo an Overgrown Succulent Garden (4:49) and
Depending on the type of succulent, how low the temperatures drop (water freezes at 32 degrees F), and how long the frost lasts, plants may show damage only on leaf tips or collapse into mush. When moisture in the cells of a frost-tender plant freezes, it expands and bursts cell walls.
However, some succulents do have a built-in antifreeze, and can survive temperatures well below 32 degrees F—below zero, in fact. Learn more about them on my Cold Hardy Succulents page.
Wait until spring to trim damaged tissue. In winter, check the weather report for your area and cover susceptible plants with frost cloth, floating row covers, or bedsheets.
- Not serious if caught early
Gophers are fist-sized mammals that live underground. If you notice a low mound of fresh soil a foot or so in diameter, or a hole that has been plugged from below with soil, you probably have a gopher.
If an agave keels over and theres a clean, concave depression at its base, a gopher likely got it. However, more often the cause of agave collapse is snout weevil.
Ive singlehandedly caught several dozen gophers and taught my son, neighbors and even gardeners how. If I can do it, so can you. Find out How I Get Rid of Gophers.
Hail damage on echeverias, two weeks later
Pock-marked and pitted leaves of succulents often result from impact damage. Not surprisingly, soft-leaved and thin-skinned succulents are especially susceptible.
Prior to a winter storm that might bring hail, move vulnerable potted plants beneath an overhang. Protect in-ground succulents with a lightweight mesh that won’t crease or break leaves and that will let rain through. I create a makeshift lean-to of old window screens.
Anthracnose on mangave (treat with fungicide)
What looks like bits of white lint in leaf axils are mealy bugs. They wont go away on their own, and can spread rapidly and infest other plants. They lay eggs in tiny cracks and crevices, so even if your plants seem fine, pests may lurk. If the infestation is serious, start over—with clean cuttings from existing succulents or new plants altogether—in a different location.
- Persistent in damp climates
- Unsightly but seldom fatal
Dry-climate plants like succulents need low humidity and infrequent water. If leather mildews where you live, your succulents likely will too. Those from arid climates dont thrive in moist, humid, rainy conditions. A tendency to mildew and rot, plus a need for nights colder than days, are generally why its difficult to grow succulents in the southeastern US, Hawaii, the Philippines and other tropical regions. You can treat with a mildew spray (like those sold for roses), but the problem will likely persist.
Also see Black Spots, Mildew, Rust-Like Spots
Rabbit and squirrel damage
In areas where predators like coyotes are kept out (like gated communities), rabbits and squirrels tend to proliferate. Measures that may help include: Installing an owl box; dusting the plants with crushed red chilis or spraying a repellent. Also, solar- and battery-powered electronic devices repel small mammals by emitting a high-frequency sound.
Mushy tissue at a succulents core results when its roots sit in water and rot. If the plant has collapsed, or its leaves have fallen off and the core is mushy, its not salvageable. If theres still some healthy tissue, remove the plant from its pot or garden bed and trim away damaged stems and leaves until you have a clean, unblemished cutting. Replant in fresh soil that drains well. See my videos, The Squish Test for Succulents (3:36) and Why Succulents Rot and How to Prevent It (2:02).
- Serious, can be fatal
Endophyllum sempervivi is a fungus similar to the “rust” that affects rose bushes. Its not especially aggressive, but it does spread, and can even be deadly. So if it pops up, dont bother treating it with fungicide. Bag the plant and put it out with the trash. From Europe, the fungus is known to affect sempervivums, aeoniums and echeverias, and potentially other soft-leaved succulents in the Crassulaceae family.
Grayish-white or brown dots that pepper a succulents skin are scale insects, which latch onto the plant and consume its tissues. The pests hard outer shell protects them like armor and makes them difficult to get rid of. Its generally best to bag the plant and put it out with the trash. Thoroughly clean the area around it, and dont put another one in that location for six months.
To prevent scale infestation, when potting succulents, add insecticidal granules to the soil.
Give your indoor plants good air circulation and check them often. At the first sign of scale, isolate the plant so it doesnt spread. Scrape off the pest with a plastic knife, wash the leaves with Safer soap, and spray with Neem oil. If your opuntia (paddle cactus) has fuzzy white dots, scroll up to COCHINEAL SCALE.
- Seldom serious, but unsightly
Snails latch onto leaves and gnaw on them, creating thumb-sized oval holes. Hand-pick the pests and treat the infested area with a biodegradable snail bait thats nontoxic to pets, such as Sluggo.
Plants eventually outgrow the damage.
Guidelines for Diagnosing Plant Problems
FAQ
How to treat succulent diseases?
What is wrong with my Aeonium?
What is the disease in the Tree Aeonium?
How do you save a diseased succulent?