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trailing begonias

I have trailing begonias I have over wintered wrapped in newspaper in my cool garden shed with good airflow. When do I get them out and pot up, and does it matter what compost I use? Also where do I keep them after I have potted them?


  • Birdy13Birdy13 Posts: 595

    I successfully overwintered begonias from 2013 last year (2013-14) by allowing all the soil on them to dry out and then knocking it off carefully and keeping them in boxes and trays on thick newspaper, but not covered up (To avoid mould).

    Around Feb /March 2014 I covered them in trays of slightly damp general purpose compost and left them for a few weeks just keeping the compost slightly moist. Eventually new shoots appeared (Around April). That's when I potted them into troughs, pots and hanging baskets.

    I did the drying out process again this year by putting them on a rack to air dry.  The reviving stage has been less successful because I think I accidentally used a mixture of new compost and spent compost. Nothing happened. I thought I'd lost them but on uncovering them all discovered that most of them are just about showing new growth at last. I've recovered them with new compost and abject apologies for mistreating them and am now hoping I've done enough to bring them back. In the meantime they staying in the greenhouse until I'm sure there's no more risk of frost.


  • Thanks Birdy13. Obviously I am a bit behind but hopefully they will catch up!

  • Right now I've potted them up, I'm not sure where to put them as I don't have a greenhouse. I have a garden room which is south facing so gets extremely warm. Do I put them on the windowsil where they will get really warm, or further back where they will get the light but not so much heat? Or am I making this all too complicated?!

  • LynLyn Posts: 23,190

    Put them further back.

     I start mine off in any old rubish compost from old plant pots, used seed compost, etc, start off in seed trays with the compost just around the edge of the corm, not on the top where the shoots will come from.

    I store the old compost in a bag through the year and  use for starting off begonia corms and dahlias tubers,  pot on in good compost when shoots are about 3 to 4  inches tall.

    Gardening on the wild, windy west side of Dartmoor. 

  • Cheers Lyn, will go back and remove the compost that is covering the corms!

  • Only one of my trailing begonias I over-wintered is shooting. Is this the only one that is any good or do I give the others a bit longer to see if they shoot?

  • Birdy13Birdy13 Posts: 595

    I've had similar uncertaintIves this year:

    over winter I have kept my tubers dry then put them in dampish compost (see 16april post). Note: dampish, not wet. Have they got too wet and rotted (feel squishy when pressed)? The healthy corm will be quite hard when the sides are pressed - don't press top and bottom or you'll damaged any emerging shoots.

    I'm still learning myself, Duchess,  and am never sure which of these can delay shooting: compost too old or too new? too dry or too damp? storage conditions too warm etc but it might be just a question of time:

    4-6weeks ago only about 70% of my corms had begun to shoot but a more experienced gardener encouraged me to give the slower ones longer: I've now got about 85% success! They are all bursting to be potted up, some lush leafy growth almost 8 inches high. I'm hopefully getting them into their summer homes today - just gearing up my mind for all that potting up.

    Perhaps you could separate the 'slow' ones from those  which can be potted up and change something for the slow ones - compost perhaps. Then, if they've not rotted, just give them longer. That's what I'm doing.


  • Thank you for your help again. Have decided as I don't need the pots for anything else I will leave them in and put them outside and if they shoot they do and if they don't they don't. Two trailers got left outside in their clay pots all winter as I missed them somehow, and they are both looking good, much further on than the ones I put in the shed. Then today I was emptying another large clay pot to put new plants in and I found a corm upside down in the pot and it had started to shoot out of what I thought was the bottom but obviously was really the top! So that one has been upsidedown and outside all winter. Do you sometimes get the feeling that some plants just really want to live no matter what, and others just don't?image

  • Birdy13Birdy13 Posts: 595

    A plant''s life force is something we could all learn from I expect.

    A propos my earlier post - just found some in my tray of 'no hopers' image are beginning to sprout at last. So there you go! image

  • Nanny BeachNanny Beach Posts: 8,717

    I have kept corms for several years now, just removed the compost, laid them in the greenhouse to dry, (have done same with shed in the past) then just leave them in empty seed tray, over winter,. April, shallow seed tray, multi purpose compost, almost on the top, not covered with compost, they would be happy in your garden room, but maybe keep them out of direct sunlight, little water AROUND the corms.   They do start off at different rate, I have some which I planted in pots at Easter, 6 inches tall, some just sprouting.  Just planted a big tub I have, there are fibrous Begonias in there, the little jobbies with maroon leaves and tiny red flowers. Meant to be annual, this is the second winter they have survived outside.  Mind you I have never managed to save Dahlias, but last year I covered one with straw, and a hanging basket to keep the straw in place, it has come back, as has one near it, which just got forgotten about, very near it, in the same bed. So, pleased about that.

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