Potting Old Begonia Tubers In Propagator

Raising the heat and lowering the humidity in the propagator creates its own problems. This old begonia tuber (the half tuber which had developed buds) is now too dry.

After carefully removing any old compost with a brush, I sprayed the dry roots and base of the tuber with lukewarm water, then re-potted into multi-purpose compost in a 5 inch half pot.

Although everyone seems to advocate placing tubers onto damp compost and then potting up when buds appear, I prefer to pot up at the start, and to cover over the tuber with compost as soon as possible. Were I not after cuttings, I would have used a deeper pot and covered the tuber to a depth of at least half an inch (1.25 cm). I don't like the idea of disturbing the delicate new roots unnecessarily, once they have formed. And my begonias have always grown well this way.

The compost is not as wet as it looks in the photo - the same wetness as used for propagating cuttings (just so that water does not run out between the fingers when squeezed hard in the hand).

Temperature can be kept at 18 -21 deg C (64 -70 deg F), and vents left open. Might have to cover with fleece overnight.