This is always a concern for me, too, and there never seems to be a set length of time for dormancy. I've found that the plant will usually let you know when it wants to grow again - you'll see little green growth points beginning to show when that happens. Until then I just keep the dormant tubers on the dry side (but never let them become dessicated); I sometimes group those plants together, let them become almost dry, and seal them in ziplock bags or clear plastic containers so I don't have to worry about them until they begin growing actively again. Maybe some more experienced growers have more exact suggestions, but this seems to work for me, as long as I don't seal up the plants with too much moisture in the bags (it's a tricky call, sometimes.)

Thank you for your reply. The ziplock sounds a good idea, it will stay dry with a little moisture. I checked it today and the soil still needs to dry out some before I bag it. I hope it comes back, I'll be really sad if I've lost it.

Is this something all the plants might do? Just like the store gloxenias? I have only grown the little sinns in the terranium and they have never gone dormant, so this is new to me.

thanks, tish

Florist gloxinias (peloric variants of Sinningia speciosa) will definitely go dormant at times; I usually grow a few outdoors in the summer, purposely letting them dry out in late fall and storing them (like potatos) in the garage through the winter. In the past couple of years I've dealt with a couple of these that were potted in something that behaved like florist foam, holding huge amounts of water for long periods of time. Plants potted this way (it's probably potting soil heavily blended with water-holding polymers) don't do well for me at all. I've nearly lost two to rot before rescuing them and repotting them in good potting soil with decent drainage. The problem with this is that the leaves wilt as the roots begin to decay, making the gardener think they need MORE water, and the vicious cycle of rot continues. Anyway, I have some mini and dwarf sinns which never go completely dormant, but they almost all go through a sort of rest period after flowering, during which I scale back watering to some degree. A lot of mine are grown outside, so they are forced into dormancy over winter.

Here's a good website I found that details growing several species of sinningias - you might find some useful info there.

Here is a link that might be useful: Sinningias and friends website