I'm having trouble rooting cuttings of the fuzzier trailing columneas. I have no problem with the shinier leafed varieties. Does anyone have any tips?
Can you give us some names?--if you know them. I have never noticed this, and am wondering if it is possible you have something other than columneas for either the shiny leafed ones or the hairy ones. Though, they do come in a range of hairiness from pretty smooth to somewhat fuzzed out. I find columneas root best if enclosed, whereas nematanthus and aeschynanthus will root uncovered in regular soil. For columneas I use my general rooting mix of perlite/vermiculite, enclosing the small pot in a ziplock bag. Then I get the best rooting when the bagged cuttings are placed on a light stand. A bright north window works too. But, cuttings will rot if not given good light. Tip cuttings of about three to six inches work best, but cuttings from lower down on young stems work well too. Check periodically and remove any rotted parts right away to prevent spread. You could go to the trouble of treating the cuttings with a fungicide as some professionals do, but I have always had good luck without it.
I bet light is it then. I stuck it in a terrarium with very low light. I'll try again with a bit more light. The one I am really trying to propagate is Lava Flow - red flowers streaked with yellow. Leaves are fuzzy for a columnea - not really really fuzzy. My favorite of the hybrids. I could give it the orchid treatment (Physan20) for the rotting issue too....
Komi, it definitely sounds like a problem of too little light. Over the years I slowly figured it out. My light stand now is a sea of little cuttings and plants living in their ziplock environments. It doesn't look so great but I keep these myriad plants going when I don't have time or room to grow them on to big plants.
I have heard of 'Lava Flow' but never grew it. 'Julia' is a great hybrid with red flowers. It has somewhat hairly leaves too. I don't have it now, but remember it to be one of the prettiest columneas. Cuttings also root very well in long fiber sphagnum moss, but then you are confronted with the problem of separating the rooted cuts from the moss to pot on. So, I use perlite/vermiculite. It seems to promote much less rot than mixes with the above two plus peatmoss.
Thanks, Jon. The lava flow has buds right now and I'll post a pic when they bloom. (Assuming that what I saw on it in passing this morning was dust and not bugs.) It needs a trimming as the old growths defoliated when I let the temperatures drop last winter.