I posted last year about my Crassula Ovata, although at the time I didn't know what it was called. I asked if anyone could identify it for me, and Muppet very kindly did, though by an alternative name Crassula Argentea. I then checked on the net and found that it was supposed to flower at Christmas. Would mine? It hadn't last year, and the net was full of people saying that theirs never had. I found out they would only flower if they had natural conditions of reduced daylight hours - well, mine had been inside all last winter, under artificial lighting. Maybe that was the answer. I decided to risk the cold and leave it outside, though sheltered this year. And the result is in the top photo. Not a whisper of a flower.
So imagine my surprise when I got to Germany for Christmas and found two large specimens in full flower growing in the entrance hall to my sister-in-law's apartment. What, I wondered, was the secret? So when I got back I set about some more research and came up with the site of The Liverpool Branch of the British Cactus and Succulent Society. It's not definitive, just an enthusiast (Jim Mercer) writing about his own experience. But I like it for that.
According to Mr Mercer, various conditions have to be fulfilled if the plants are to flower. Apart from the light conditions mentioned before, he suggests that the plants must be about four years old and a foot tall. Mine is just about that, perhaps a bit less. If that's all though, next year there should definitely be flowers.
He also warns against pruning too late in the year as the flowers form at the end of branches. I didn't prune at all this year, so it's not that, but I shall have to sooner or later. Otherwise they can reach 7ft tall! He suggests June as being the optimum time.
Then there's feeding and watering. C. ovata are dormant in summer, but Mr Mercer advises watering and feeding (reduced strength) weekly. Oddly he doesn't talk about feeding in winter when they're active, but in any case I didn't feed at all this summer. Next summer I'll try it.
I suspect the real reason I'm not getting flowers though, is temperature. Mercer recommends greenhouse conditions in winter, with a night-time minimum of 5°C. And in fact, those in my sister-in-law's apartment block must have just about the same conditions. No way I can do that inside the flat, so next year maybe I should try mine in our hallway too. I can see that I'm going to have to spend 2008 being extremely nice to the neighbours ...