I don't know if anybody else here has had trouble with Pinguicula propagation on the standard peat/perlite mix, but I have. For one, it seems the plants never develop large root systems on peat, but I have also found that cuttings often rot before growing up, or else they quit growing once they reach a certain size. I knew something was wrong, when the only cutting in a batch of p. zecheri on peat/perlite that survived was a stray that had gotten caught on the side.
So, I tried something different. Last fall, I received a plant of P. agnata x moranensis var. caudata. I dissected the plant into individual leaves, and laid them on rubber foam in a small tupperware container. Here is what they looked like after a few months:
At that time, the plants had sent roots clear through the ~3/8" foam. I split them up and put all the big specimens in baby food jars with lids designed for tissue culture. This photo was taken a few weeks ago:
The plants are now filling the jars so I won't be able to get them out without damaging the plants. They have built root systems through the 1" of foam they are in.
I don't have a lot of species to experiment with, but I have tried and had success with the following:
P. x " 'John Rizzi' "
P. x ?
If anyone else is willing to experiment as well, please do so and let me know how things turn out. Cuttings need to be placed on top of a layer of foam which is sitting in water. If you transplant, cut slits in the foam and insert the plantlets. You also may need to do this if planlets from cuttings don't manage to "catch on" to the foam.
P.S. The foam used in this experiment is the kind that egg-crate mattresses are composed of.