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I might add that you did give it a sufficient cooling period to initiate the embryonic flowers but the cooling period needs to be sustained as the stalk elongates. If it's too warm, the flowers will just open up on a stubby stalk. It doesn't have to be crazy cold though, I have good success with 18-20 degrees during the day and 12-15 at night (cooler the better). Turn the furnace down at night and get a heating blanket!

Thanks so much! The indoor temp here is actually around 18-23c. Is it cool enough? May be I could move it to the basement at night time? What about the water? I read that when you see the bud it needs lots of water to elongate. Is that true? I did give it some water this morning, I hope it's not something I shouldn't do...
Thanks again!
Th

18 degrees is too warm at night and 23 is probably a bit warm for a daytime high. Watering a Clivia is always a cautious venture. The 'soil' must be very free draining...I mix potting mix with about 25-30% shredded bark. They prefer a clay pot b/c it breathes better than plastic. In summer, let it very nearly dry out before watering. In winter (& in cool conditions), I let the soil dry out, wait at least a week, then water. Once the flower stalk appears, I wait 1-2 days instead.

It looks like a big challenge for me to keep the temp low enough for it to bloom since my chinchilla pets would like warmer than that. I hope a cooler windowsill will just do it. I also read less sunlight will yield a longer stalk?

"I also read less sunlight will yield a longer stalk?"

Yes, but in a sort of pale and sickly way.

I grow C. miniata to. For years the stalk never did come out of the leaves. This year I've had 2 do it, both flowered in the fall. The one is still flowering now. Both had stalks that rose as the buds opened. I don't have the cold room anymore so mine don't get the cold period. They flowered anyway, the best ever. I didn't realize they needed the cold for the stalks to grow taller. Thanks for that tip Smivies. I asked questions on the clivia forum and was told they need phosphorous for the stalk to get taller. I'm trying that, alternating between a general fertilizer and with more phosphorous in it.