Coaxing tubers and rhizomes into growth

I would really like to thank Sal and Kristen for this video (from the Colocasia thread) I found it most useful and thought provoking.



I have followed the instructions and my Eddoes (Colocasia) are now in a polybag in a heated propagator. However it set me thinking that this principle is totally logical, and I see no reason why it shouldn't be used for all manner of different tubers and rhizomes. I have been looking at my Amorphophallus which has only just started to move within the last few days (its now also in the propagator). Even though it was previously inside the house, it clearly wasn't getting enough heat.

But why I am writing this is to point out that a heated propagator is not at a uniform temperature. When I first bought my propagator, I played about with it and very quickly realised that because the heat was applied at the bottom there was a big temperature gradient from bottom to top. My thermostat is set from a sensor which is inserted into the top of a small pot of compost and currently reads 27C. But when I put another sensor under the pot, at the very bottom, I found it was reading about 43C (ie 110F). Now thats a very different temperature.

I have left some Eddoes in pots where they are experiencing the 27C, but I also put some in a polybag sitting on the bottom where they experiencing the 43C. That will either put them into overdrive or cook them. Using a pot is clearly not the same as using a polybag.

 

Peter to my experience , I tryed the bag in March and work really well , in the past as I didn`t had any clue , i planted straigh in the soil and they came out with no problem , once I`ve even put in a pot and straigh in the pond covered by 2 inch water , no problem at all.
For some reason the small round one are more hard to start then the long ones , one year I`ve simple got polyester cups and filled with water , they come out no problem , but i think it`s all about the eating.
Be generous and put as many as you can in one pot , they will look stunning.
About moltiplication , there are some really easy to get cutting and other that just don`t do anything , if you are lucky you should have some runner coming trough in spring if left in water.


this one has been overwinter in the greenhouse and left water at the bottom , that why has managed to produce offset.

 

Thanks Sal. Yes, they are so cheap from a supermarket that I will certainly be getting some more. I have some other question about Colocasia - but will put them back on the Colocasia thread.