overwintering rhizomatous Gesneriads

[Uli]

Following a question after my donation of Achimenes and other rhizomatous Gesneriads to the EU BX, here is how I get them through the winter.
In autumn I try to keep the vegetation going as long as possible after flowering. This ensures good and healthy rhizomes. I keep fertilizing with a general fertilizer rich in potassium to build up the scaly rhizomes. Once the plant goes dormant I stop watering immediately and move the pot into a room with about 12-15 degrees centigrade. The rhizomes remain in their pots in the substrate which should be completely dry. A trap to avoid is residual moisture in larger plastic pots which might lead to rot during dormancy. Overwintering the dormant pots in a cold but frost free greenhouse has led to almost total loss, it was too cold. Repotting takes place around this time of the year and the rhizomes are started with gentle bottom heat until shoots are visible. I do not store dormant rhizomes in bags: in paper bags they dry up too much and in plastic bags they might rot. Storage in the dry substrate has proven to be best.
The same procedure applies to Caladiom tubers, they are even more sensitive to too cold storage condition.
Attached is a picture of X Smithicodonia 'Heartland's Joy', a reliable hybrid