Gadenin日本語Get the appThe shape of the year
Everything a cymbidium does is a year behind the conditions that caused it. The growths that appear in spring fatten through summer, mature in late summer, take their cold trigger in autumn, and open flowers in winter. That means a flowering failure this winter is almost always the result of something that happened last summer, and no amount of attention in the flowering season can repair it.
Once you see the loop, care becomes a matter of not missing a handover. Push growth hard in spring and summer, ease off the nitrogen and let the autumn cold do its work, hold everything cool and steady through flowering, then repot only if needed and start the cycle again. The plant does the rest.
The table below is the whole year at a glance. Read the season names as descriptions of conditions rather than months, since the plant responds to light, temperature and its own maturity rather than to a date.
| Season | Position | Water and feed | Main job |
|---|---|---|---|
| Late winter to early spring | Cool bright indoors, in flower | Water every 10 to 14 days, no feed | Enjoy the flowers, keep the room cool |
| Spring, after the last flower | Still in, moving out once nights hold above 45F (7C) | Water more as growth starts, begin balanced feed | Cut spent spikes, repot or divide if needed |
| Late spring | Outdoors, hardened off in stages | Water freely, balanced feed every second watering | Acclimatize to light without burning leaves |
| Summer | Outdoors, morning sun and afternoon shade | Water daily in heat, feed every second watering | Fatten the pseudobulbs, watch for pests |
| Late summer | Outdoors, full light as the sun weakens | Water well, switch to low nitrogen and high potassium | Harden the growths, stop pushing leaf |
| Autumn | Outdoors through the cold nights | Water every five to seven days, feed lightly | Take the cold trigger, watch for spikes and slugs |
| Late autumn, first frost forecast | Into a cool bright room, porch or greenhouse | Reduce water, stop feeding | Stake the spikes, then stop moving the plant |
| Winter | Coolest bright indoor spot, 50F to 60F (10C to 15C) | Water every 10 to 14 days, no feed | Buds swell and open, keep still and cool |
Spring: reset the plant
As the last flower fades, cut the spike off at its base with a sterile blade. Then decide about repotting, and be reluctant. If the bark is still chunky and drains freely, leave the plant alone even if the pot looks crowded, because crowding is what makes it flower. If the mix has gone dark and fine, or the growths are hanging over the rim, this is your one good window and you should take it now rather than later in the season.
New growths appear at the front of the plant as the light strengthens. That is the signal to raise the watering and start feeding with a balanced orchid fertilizer at every second or third watering. A plant that is fed hard from the moment growth moves makes bigger pseudobulbs, and pseudobulb size is what decides whether there will be flowers eighteen months from now.
Move the plant outside as soon as nights hold above 45F (7C), but harden it off over two to three weeks. Full shade first, then morning sun only, then its summer place. Leaves that have spent the winter indoors scorch in a single unshaded afternoon.
Summer: build the growths
This is the only part of the year where the aim is simply to grow the plant as hard as possible. Strong light, plenty of water, regular feeding, and enough space around the plant for air to move. A mature plant in hot weather may want water every day, and it will not object, because it is sitting in coarse bark on a well-drained surface.
The one thing to watch is leaf color. Aim for a stiff, upright, light yellow-green. If the leaves are dark and floppy, the plant needs more light and you should move it to a brighter spot in stages. If pale patches with a dry papery feel appear, it needs more shade at once. That color is the running score for next winter's flowers.
Inspect weekly for pests while you are watering, and turn a leaf over each time. Summer outdoors is when scale, mealybug and aphids arrive, and all of them are easy to remove early and hard to remove late.
From midsummer onwards, change the feed. Drop the nitrogen and move to a low-nitrogen, high-potassium formula. Nitrogen late in the season keeps the plant making soft leaf when it should be hardening its growths, and soft growths do not respond to the autumn cold.
Autumn: the part most people get wrong
Leave the plant outside. That is the whole instruction, and it is the one that decides whether you get flowers. The chilly nights of early and mid autumn, with nights of 45F to 55F (7C to 13C) against warm days, are what initiate the spikes. Bringing the plant indoors when the evenings first turn cool feels like care and costs you the season.
Watch the base of the mature pseudobulbs from late summer onwards. When a pointed shoot appears, roll it between your fingers: round like a pencil is a flower spike, flattened like a folded fan is another leafy growth. Once you have confirmed a spike, put a cane in beside it while it is still short and flexible, and add a tie every few inches as it extends.
Bring the plant under cover only when frost is genuinely forecast, and choose the coolest bright place you have. Once it is in and the buds start to swell, stop turning the pot, stop moving the plant, and keep it away from radiators and ripening fruit. From that point the plant needs stillness more than it needs anything else.
Winter, and the notes that make next year easier
Through flowering, hold the plant at 50F to 60F (10C to 15C) in bright light, water every ten to fourteen days, and do not feed. Cool is what makes the flowers last two months or more instead of three weeks. Keep water off the blooms and keep gentle air moving, so botrytis spots do not appear on the petals. When the last flower is over, cut the spike and the loop starts again.
Keep a short annual record, because a cymbidium year is too long to hold in your head. Six entries are enough: the date the plant went outside, the lowest night temperature it actually experienced in autumn, the date it came indoors, the date the first spike was confirmed, how many spikes there were and from which pseudobulbs, and the date the first flower opened.
After two years those notes will answer most of your questions without any guesswork. If spikes never appear, compare the autumns and you will usually find the plant came in three weeks too early. If spikes appear but flowers are short lived, the winter room is too warm. If the plant does neither, look at the pseudobulb size from the previous summer, and the answer will be light.
Also note the year you last repotted and the grade of bark you used. A season where the watering interval suddenly shortens or the plant sulks for no visible reason is almost always a mix that has broken down, and the potting date is the quickest way to confirm it.