Gadenin日本語Get the appSudden leaf drop is a chill until proved otherwise
The single most reported problem with this plant is a rapid loss of green, healthy-looking leaves over a few days, with no yellowing beforehand. People reach for the watering can, either giving more or stopping altogether, and neither helps because neither is the cause.
Lipstick plant reacts to cold at the roots and cold on the leaves by shedding. Water straight from the tap in winter can be in the low fifties Fahrenheit (around 11C), and pouring that into a root ball sitting at 70F (21C) is enough on its own. So is a draft from an outside door, a gap under a sash window, or the cold air that falls off single glazing on a frosty night. Below about 55F (13C) the plant starts dropping leaves within days.
Work through the possibilities in order: what temperature was the water, where does the plant sit relative to doors and windows, and how cold does that spot get overnight when the heating goes off. Fixing the chill stops the drop within a week or two, though the lost leaves do not come back on the same wood.
Leaves lost from a chill leave bare stems that will not refoliate. Cut those stems back after the next flowering and use the prunings as cuttings rather than waiting for the gaps to fill.
Mealybug lives where you do not look
Mealybug is the pest this plant gets most often, and the trailing habit is why it goes unnoticed. The insects sit in the leaf joints along the undersides of the hanging stems and in the crown at the center of the pot, which is exactly the part of a hanging plant you never see from below.
Look for small white waxy blobs like specks of cotton wool, plus a sticky film on leaves and on whatever sits under the plant. Heavy infestations distort new growth and cause buds to abort before they open. Check by lifting a hanging plant down and turning the stems over, once a month during the growing season and again before you move it into its cool rest.
Treat on sight rather than waiting to see how bad it gets. A few insects picked off with a cotton bud dipped in rubbing alcohol ends the matter; a colony that has spread into the crown and the top of the compost takes months and usually costs the season's flowers.
| Pest or problem | First sign | Where to look | Treatment |
|---|---|---|---|
| Mealybug | White waxy specks, sticky leaves | Leaf joints, crown, stem undersides | Alcohol on a cotton bud, then insecticidal soap weekly for a month |
| Spider mite | Fine speckling, dull leaves, webbing at tips | Leaf undersides, growing tips | Raise humidity, rinse foliage, repeat sprays every five days |
| Scale insect | Hard brown limpets on stems | Along older stems, leaf midribs | Scrape off, then insecticidal soap |
| Root rot | Yellowing from the base, sour smell | Tip the plant out and look | Remove soft roots, repot into open mix, smaller pot |
| Botrytis on flowers | Gray fuzz on spent blooms | Faded flowers left on the plant | Remove spent flowers, improve air movement |
Root rot, and telling it apart from drought
Root rot and underwatering both produce limp, dull foliage, and the instinct in both cases is to water. That instinct kills the rotting plant. The distinguishing test is the compost: a thirsty plant has dry compost that has shrunk away from the pot sides, while a rotting one has compost that is still wet several days after the last watering and smells sour when you put your nose to it.
If it is rot, act the same day. Tip the plant out, wash the old mix off the roots, and cut away everything brown, soft or hollow. Healthy lipstick plant roots are pale and firm. Repot what remains into a genuinely open mix, half potting mix with a quarter perlite and a quarter fine bark, in a pot that fits the surviving roots rather than the old root ball, and keep the plant warm and only just moist while it recovers.
Take cuttings from the healthiest stems at the same time, before you find out whether the parent survives. It costs nothing and it is often the only part of the plant you keep.
Failures that are not diseases at all
A good proportion of what gets reported as a problem with this plant is normal behavior being misread, and treating it makes things worse.
- It never flowers Almost always either pruning in the weeks before the season, which removes the flowering tips, or the absence of a cool drier rest. Neither is a disease and no feed will fix it.
- Buds drop before opening Caused by the pot going dry during bud development, or by the plant being turned or moved while buds are forming. Keep it evenly moist and leave it facing the same way until the last flower falls.
- Bare stems with tufts at the ends Normal ageing, not neglect. The plant does not refoliate old wood. Cut back after flowering and root the prunings rather than trying to nurse the bare sections.
- Brown crisp leaf tips Dry air or a build-up of fertilizer salts. Flush the pot with several potfuls of plain water, raise humidity, and feed at half strength rather than full.
- Pale washed-out leaves in summer Too much direct midday sun. Pull the plant back a foot or two from the glass rather than moving it into a dark corner.
Keep a note of what appeared and when
Pests on houseplants are seasonal and repeat. Spider mite arrives when the heating comes on and the air dries out; mealybug builds through the warm months and is often brought in on a new plant. Writing down what you found, on which plant and in which month turns a run of separate crises into a predictable calendar you can get ahead of.
Record the treatment dates too, because most of these pests need repeat applications five to seven days apart to catch the eggs that survived the first round, and a single treatment followed by a relapse is the usual reason people conclude a product does not work. Note also where the plant was standing when the problem began, since the drafty corner or the too-bright shelf tends to cause the same trouble again the following year.