Propagation log: twelve ghost plant leaves through an indoor winter
Leaf propagation usually stalls in winter because light and temperature both drop. This batch was run deliberately indoors from 22 September 2026 on a shelf with supplementary light, to see whether a winter batch is worth starting at all. Twelve leaves, eleven plants.
The setup: two variables held constant
Twelve leaves were taken on 22 September from a single Graptopetalum paraguayense, laid on dry 3–5 mm grit, and kept on a shelf at 19–22 °C under a 40 W LED bar giving about 9,000 lux at leaf level for 12 hours a day. No bottom heat, no cover, no misting for the first 19 days.
The two variables that normally stall a winter batch — temperature and light — were therefore both held near their summer values except for the light, which was roughly a third of outdoor summer levels. The trays were 25 cm below the bar, and the bar was moved up by 5 cm every two weeks as the pups grew to keep them from scorching.
Timeline, and how it differed from a summer batch
Callus formed in 4 days, essentially the same as in warm conditions. Root initials appeared at day 13–16 and visible roots at day 19–24 — only two to four days slower than an August batch run the same way.
The real difference was in the pups. First visible rosettes appeared at day 38–50 versus day 26–34 in summer, and the pup-to-parent-leaf size ratio at 60 days was 0.35 versus 0.55. Development was slower, not blocked, which is the important finding: a winter batch works, it just takes roughly 40 % longer.
Watering under lights
The 12-hour light cycle at 19–22 °C meant the tray surface dried faster than the ambient humidity suggested. Water was applied by misting the surface around each leaf, 20 ml per tray, every five days from day 19, rising to 40 ml every four days from day 30.
Under lights the risk is different from a windowsill batch: the top millimetre dries out but the layer below stays damp, which is exactly the wrong gradient for a leaf that is trying to root into the surface. Propping each leaf on a 3 mm layer of coarse grit so its base sits above the fine material solved it.
Result at 90 days
At 90 days, 11 of 12 leaves had produced at least one pup (92 %), with 11 pups in total and one leaf producing two. Pup diameters ranged from 9 to 16 mm and the parent leaves were still attached and about one third of their original thickness.
They were potted on at day 95 into 6 cm pots, leaving the parent leaf attached for a further six weeks. The single failure was a leaf that had been knocked off the shelf at day 20 and landed face-down on the damp layer; it rotted at the scar within four days.
Stage-by-stage numbers
| Stage | Day | What to look for |
|---|---|---|
| Leaf pulled | 0 | Petiole intact and the break is clean; dry, curved side up |
| Callus | 4 | The break seals and dries without blackening; still no water |
| Roots | 23 | Root tips past 5 mm; begin wetting the surrounding surface |
| Pup | 52 | Pup at 15 mm with its own stem base; ready to separate |
Stage comparison
Batch started 22 September 2026; 12 samples, 92% success.
Four things to take away
- A winter batch works — it runs about 40 % slower, not not at all.
- 9,000 lux at leaf level for 12 hours was enough to keep pups forming.
- Prop the leaf base above the fine material so the damp layer sits below the scar.
- 92 % strike rate over 90 days; leave the parent leaf on for six more weeks after potting.
Informational only — This page is a cultivation record, not horticultural or plant-pathology advice. Any treatment should follow the product label and local regulation.