Gadenin日本語Get the appFollow the growth cycle, not the calendar
A cattleya lives in stages. A new growth pushes from the base of the last pseudobulb, expands over several weeks, hardens into a bulb of its own, makes a sheath, pauses, flowers, and then rests before starting again. Every job in the year hangs off that cycle rather than off a month, which is why an owner in one hemisphere and an owner in the other can follow the same instructions.
Different cattleyas run this cycle at different times, and some plants run through it twice a year. So the first job of any year is to work out where your own plant sits. Look at the newest bulb: soft and expanding, hard with a green sheath, hard with a dry sheath, or in flower. That tells you which row of the table below you are in.
The other rhythm that overlays this is the season outdoors, because light and temperature change whether the plant is growing or not. Strong light and warmth push the growth stage along; short dim winter days slow everything down. Where the two conflict, the plant's own stage wins for watering and feeding decisions, and the season wins for where the plant stands.
| Stage | What you see | Water and feed | Main job |
|---|---|---|---|
| New growth starting | A pointed shoot pushing from the base of the newest bulb | Water when dry, start feeding at quarter strength | Repot now if the mix is spent and roots are showing |
| Growth expanding | The shoot lengthening, leaves unfurling, roots running | Heaviest use of the year, feed most waterings | Maximum light without burning, keep air moving |
| Bulb hardening | Growth stops lengthening, bulb fattens and firms | Ease back slightly, keep feeding | Do not disturb, let the bulb finish |
| Sheath formed, waiting | A flat green sheath at the top, then drying to beige | Longer intervals, light feeding | Leave the sheath alone, give a cool night drop |
| Buds and flowering | The sheath swelling, buds emerging and opening | Steady, no sudden changes, stop heavy feeding | Stop moving the plant, keep water off the flowers |
| Rest after flowering | Nothing moving, bulbs hard | Water sparingly, no feed | Wait for the next growth and root initials |
Warm months: the year's real work
The season of long days and warm nights is when a cattleya builds everything it will spend later. This is when to give it the brightest position it can take, when to feed, and when to accept that it will need water every four to seven days. A bulb built in strong light in these months is the bulb that flowers, so effort here pays and effort in winter mostly does not.
Once nights hold above 55F (13C), moving the plant outdoors into dappled shade is the single most effective thing you can do for it. Harden it off over two to three weeks so the leaves do not burn, and stand the pot on a bench or slab where slugs cannot climb into the drainage holes.
Feed a balanced orchid fertilizer at about a quarter of the label strength with most waterings while a growth is expanding, and flush the pot with plain water every fourth watering to wash salt out of the bark. Stop feeding when the growth stops lengthening. Feeding a plant that has finished growing achieves nothing except a build-up of salts.
Cooling weather: cue the flowers, then bring it in
As nights cool, the day-to-night temperature swing widens, and that swing of 10F to 15F (6C to 8C) is part of what pushes a matured bulb towards flowering. Let the plant have those cool nights outdoors for as long as it is safe, which usually means until nights approach 55F (13C).
Bring it in before it gets cold rather than at the first frost warning. Cattleyas are not cold-hardy; anything below about 45F (7C) marks the leaves. On the way in, inspect the plant thoroughly, peel back a bulb sheath to check for scale, hose the foliage off and let it dry, and keep it apart from the rest of the collection for a fortnight.
Indoors, put it in the brightest window you have and start stretching the watering interval, because a cool room with short days dries a pot far more slowly than a warm summer bench did. This is the point in the year when most cattleyas are lost, and almost always to watering on summer habits in winter conditions.
If buds or a swelling sheath are on the plant when you bring it indoors, choose its winter position on the way in and then leave it there. Turning or relocating a plant with developing buds is a common cause of crooked flowers and bud drop.
The cold, dim months: hold, do not push
Through the darkest part of the year a cattleya is largely holding position. Water only when the pot is genuinely light, which may be every ten days to three weeks, and do not feed. Keep it in the brightest glass in the house, away from radiators and heating vents, with a night temperature of 55F to 60F (13C to 18C) if you can manage it.
Do not repot now, even if the mix looks tired, unless the plant is actively rotting. Cut roots will not regrow until the next growth cycle, and a plant repotted in midwinter sits root-bound and vulnerable for months. Note the job down and do it when root initials appear.
Slight wrinkling of the oldest pseudobulbs at the end of winter is normal and does not call for more water. Deep grooves on the newest bulb do call for tipping the plant out and checking the roots.
Keeping a record that pays off
Because a cattleya's cycle can run out of step with the seasons and can shift year to year, memory is a poor guide. Keep a simple line per plant per event: the date a new growth appeared, the date it stopped expanding, the date a sheath formed, the date buds became visible, and the date the first flower opened.
After two cycles that record answers the questions that otherwise cause mistakes. It tells you how long your plant's pause between sheath and bud runs, so you do not cut a good sheath off. It tells you when to expect the root initials that open the repotting window. And it tells you whether a year without flowers followed a summer in a shadier spot, which is usually the real answer.
Add the window each plant stood in and the lowest night temperature it sat through in autumn. Those two facts, set against whether the plant bloomed, are worth more than any general rule about cattleyas.