Echeveria Problems: Summer Rot, Mealybugs, Fungus Gnats and Scorch

What actually goes wrong

The list of echeveria problems is short, and most of it is caused by the grower rather than by anything arriving from outside. What makes this plant unforgiving is the speed difference: rot can take a healthy rosette down in three or four days, while everything else moves over weeks.

Before you do anything, push a finger into the compost. Damp compost and dry compost point at completely opposite answers, and treating overwatering with more water is the most common way a recoverable plant is finished off.

Summer rot: the one that kills

Rot is not something a plant catches. It is what happens when roots sit in wet compost without air, and warmth accelerates it enormously, which is why the losses cluster in muggy summer weeks rather than in winter. A rosette that looked fine on Monday can be a soft heap by Friday.

It shows first at the bottom. Lower leaves go yellow, then translucent and squashy, and drop at a touch, and the stem behind them turns brown and soft. Squeeze the stem just above the compost: firm means you have time, soft means act today.

1. Take the plant out of the pot immediately Do not water it and do not wait to see. Tip it out, crumble the compost off the roots and look at the stem. Healthy tissue is pale and firm, rotted tissue is brown, soft and often smells sour.
2. Cut up the stem until the cut face is clean With a clean blade, slice across the stem a little at a time, working upwards. Keep going until the cut face is uniformly pale with no brown ring or brown flecks in the center. A brown speck left behind carries on rotting.
3. Sterilize the blade between cuts Wipe the blade with rubbing alcohol after each slice. Otherwise you smear rot organisms from the infected tissue onto the clean cut you have just made.
4. Dry the cutting for three to seven days Stand the cleaned rosette upright in an empty pot in bright shade with air moving until the cut end is dry and corky. This cannot be shortened and it cannot be done in water.
5. Reroot dry, into fresh gritty potting mix Set the callused stem on dry gritty potting mix in a small pot. Give no water until roots appear in two to four weeks, then water lightly.
6. Save the healthy leaves Any firm leaf from the affected plant can be rocked off and laid out to propagate. Even a plant that is entirely lost usually yields half a dozen usable leaves.

Never reuse the compost and wash the pot before it goes back into service. The organisms that finish a rotting stem are already living in that mix, and a clean cutting potted into it goes the same way.

Crown rot and water in the rosette

Crown rot is the same organism working from the top down, and it comes from water sitting in the center of the rosette overnight, from overhead watering, from a downpour, or from misting. It shows as browning and softening at the very center, sometimes with the newest leaves pulling out cleanly when touched.

The plant is not necessarily lost. If the stem below the damage is still firm, cut the whole top off below the rot and reroot the clean section, exactly as for stem rot. If the rot has run down into the stem, take leaf cuttings from the healthy outer leaves instead.

1. Empty the crown every time it gets wet Tip the plant on its side and shake the water out, then leave it where air moves until the center is dry. Doing this reliably prevents almost every case.
2. Do not mist an echeveria Misting does nothing useful for a succulent, marks the farina and leaves exactly the film of water in the leaf axils that starts crown rot.
3. Keep outdoor pots out of rain Prolonged rain fills every rosette and soaks the compost at the same time. An overhang, a clear roof or a shelf under the eaves solves it completely.

Mealybugs, root mealybugs and gnats

Mealybugs are the pest that actually finds echeverias, and the tight rosette gives them perfect cover. They hide deep in the leaf axils and in the folds where leaves meet the stem, so a casual glance from above misses them until there are dozens.

Root mealybugs are worse because you cannot see them at all. The plant simply stops growing, looks dull, and stays dry-looking however you water it. Whenever you repot, look for white powdery deposits on the rootball and the inside of the pot.

Fungus gnats are not really a pest problem, they are a diagnosis. Flies over the compost mean it is staying wet for too long, so fix the watering or the mix rather than reaching for a spray.

Damage that is not a disease

Several alarming-looking symptoms are physical damage rather than anything spreading, and treating them as disease wastes effort. None of them get worse once the cause is removed, and none of them heal on the leaf they occurred on.

The general rule is that damage which is dry, sharply defined and confined to the older leaves is physical. Damage that is soft, wet and spreading into new tissue is rot.

When to give up, and what to write down

The test for whether a plant is worth saving is simple: is there any firm, pale, undamaged stem left with live leaves attached above it? If yes, cut back to it and reroot. If no, the plant is gone, but any firm leaf can still be rocked off and propagated, so you rarely lose the plant line entirely.

Record the date you last watered before a problem appeared, the weather that week, and the date you first saw the symptom. Rot in particular repeats: after one season those three figures usually show that your losses follow the same muggy week every year, and that is something you can act on before it happens again.