Gadenin日本語Get the appMealybugs hide where the leaves overlap
The tight rosette that makes this plant attractive is also the reason mealybugs are the number one pest on it. They sit in the crevices where one leaf laps over the next, and in the crown at the very center, which is exactly where you cannot see. By the time you notice white fluff on the outside of the rosette, there is usually a colony three or four leaf layers in.
Check with a torch, not with the naked eye. Shine it straight down into the crown and look for the cottony white specks and for a faint sticky shine on the leaf surfaces. Sticky leaves with no visible insect means they are further in than you have looked. Ants walking up the stem mean the same thing.
Root mealybugs are the version people miss entirely. If a plant sulks, stops growing and refuses to color up while everything about your watering looks right, slide it out of the pot and look at the outside of the root ball. White powder against the pot wall and small white clusters on the roots is a root mealybug infestation, and it will not clear up on its own.
- Spot-treat with alcohol on a brush Dip a fine paintbrush or a cotton bud in rubbing alcohol and touch every white speck you can see. The insect dies on contact. Work into the crown gently and accept that you will knock a leaf or two off doing it.
- Then drench the whole plant Spot treatment alone never gets the ones you cannot see. Follow up with a systemic soil drench or a soap-based spray applied until it runs off, and repeat at 7 to 10 day intervals for three applications to catch each new hatch.
- Bare-root and wash if the roots are infested Knock off all the old compost, rinse the roots under a tap, cut away any that are dead, and let the plant dry in the shade for two or three days before repotting into fresh dry mix in a clean pot. Do not reuse the old compost anywhere.
- Isolate the plant for a month Move it away from every other succulent until you have gone four weeks with no new insects. Mealybugs cross between touching pots faster than they cross open bench space.
Alcohol removes the waxy bloom wherever it touches, leaving a permanent shiny patch on that leaf. That is a fair trade for killing the colony, but it is a reason to use a brush rather than spraying alcohol over the whole plant.
Rot moves up the stem, and speed decides whether you save it
Rot is the only problem on this list that kills the plant outright, and it is almost always caused by compost that stayed wet, usually in cool weather or in a pot too large for the root system. It begins at the roots, works up the inside of the stem, and only shows on the surface once it is well advanced.
The first visible sign is at the bottom of the rosette: the lowest leaves go yellow and translucent, and when they drop they leave a wet mark rather than a dry scar. Squeeze the stem just above the compost. A healthy stem is firm like a green twig. A rotting one is soft and gives under light pressure, and often shows brown or black staining if you scratch the skin with a thumbnail.
Once the stem is soft there is no treatment that saves the base. What you can save is the top. Cut well above the damage, check the cut face, and keep cutting a quarter inch (5 mm) higher until the exposed tissue is clean white or pale green with no brown ring or brown flecks in the center. Then let the cutting callus for five to seven days in a shaded, airy spot and root it as a fresh plant. A graptoveria beheaded this way roots readily, which is why rot is rarely a total loss if you act the day you notice.
| Symptom | Likely cause | What to do |
|---|---|---|
| Lower leaves yellow, translucent, wet where they detach | Overwatering, rot starting at the roots | Stop watering, unpot and inspect the roots today |
| Stem soft and squashy at compost level | Rot already in the stem | Behead above clean tissue, callus, re-root |
| Brown mush in the center of the rosette | Water sat in the crown in cool weather | Usually fatal to that rosette; take leaf cuttings from healthy leaves |
| Lower leaves dry, papery, come away clean | Normal ageing, or simply too dry | Nothing wrong; pull them off and water on schedule |
| Whole plant limp but compost dry and roots white | Severe drought | Soak thoroughly; it recovers in two or three days |
Marks on the leaves that will never go away
A large share of the questions people ask about this plant are not disease at all. The leaves carry a fine powdery or waxy coating, and that coating is a one-time surface laid down as the leaf formed. Anything that removes it, whether a fingerprint, a splash of hard water, a rub against a sleeve or an alcohol swab, leaves a shiny or dull patch that stays for the life of that leaf.
The same is true of dents, scratches and hail bruises. A succulent leaf does not heal over; it only grows out. The marked leaves stay marked until they age off the bottom of the rosette, which takes most of a season. Nothing you spray will fix them, and a plant that is otherwise firm, growing and well colored is fine.
Sunburn is worth telling apart from all of that. Burn shows as pale bleached patches that later go tan or dry brown, always on the leaf faces angled at the sun, and it appears within a day or two of a move to brighter light. It is caused by the change rather than the brightness, so a plant that has been outside all season handles light that would scorch a plant carried straight from a windowsill.
If appearance matters to you, handle the plant only by the pot, water at compost level with a narrow spout, and never mist. Almost all cosmetic damage on a graptoveria comes from being touched, not from anything biological.
The smaller pests, and when to stop trying
Aphids arrive on the flower stalk rather than the rosette, clustering along the stem and buds in spring. They do no lasting harm and the simplest response is to cut the stalk off, which costs you a flower you probably did not need. Wash or spray only if you want the bloom.
Fungus gnats mean the compost is staying damp for too long. They do not damage a healthy graptoveria directly, but they are a reliable warning that your watering interval is short for the conditions. Let the pot dry out completely and they disappear.
Know when to abandon a plant. If the stem is soft more than halfway up, if the crown has collapsed into brown mush, or if a mealybug infestation has survived three full treatment rounds, the plant is not worth further effort. Take the cleanest healthy leaves off it, root those, and dispose of the rest along with its compost. This species regenerates from a single leaf so readily that starting again is often faster than nursing a badly compromised plant.
Keep a record of what appeared and when
Pest problems on succulents are seasonal and they repeat. A short written record turns each incident into a warning for the following year instead of a surprise.
Write down the date you first saw the pest, which plant it was on, where that plant was standing, and what you treated it with. Note the dates of each follow-up treatment and the date you last saw a live insect, because that gap tells you whether three rounds was enough or whether you stopped early. For rot, record the date and the conditions leading up to it: how long since the last watering, the temperature that week, and the pot size. Almost every case of rot traces back to a specific combination of cool weather and a recent watering, and two seasons of notes will show you your own pattern clearly enough to avoid it.