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Promoting Root Growth in Flasks

Discussion in 'Orchid Culture' started by Alex Shepack, Apr 6, 2022.

  1. Alex Shepack

    Alex Shepack Active Member

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    Any tips or tricks to promote root growth in flasks that are in the last stage before deflasking? Anything with temperature or light levels?

    Background -
    I often purchase Lepanthes flasks from Ecuagenera. Sometimes they come with great root growth and are ready to come out, other times they have very few apparent roots. I've tried waiting for around 6 months to remove the ones with less root growth, but it doesn't seem to make much difference. I tend to pull them regardless once I see leaf death or substantial blooming in the flask.

    This flask has pretty decent roots and I'll probably pull it soon (although I've had some come with far more root growth)

    I see very few roots in this flask, although the plants are spiking and starting to bloom.

    I'd also, in general, love to hear peoples thoughts about deflasking and how you decide when to pull.

  2. xmpraedicta

    xmpraedicta Prairie angraecoid nut Supporting Member

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    Saskatoon, SK
    Not a very experienced flasker but the few species I've done, I find replating from mother flask to replate flask is associated with a burst of root growth. I don't know if it's the increase in concentration of nutrients, or perhaps fresh media that does it, but I don't know of light/temperature that affects things. Certain hormonal additives can also promote proliferation of undifferentiated callus growth. I recently imported a flask that was overcrowded and underdeveloped and replated the seedlings onto replate flasks as well as mother flask media with and without coconut to see what would happen.
    J E and Alex Shepack like this.
  3. Chuck-NH

    Chuck-NH Well-Known Member

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    New Hampshire, USA
    I agree with Calvin that replating usually is followed with a “burst” of root growth as well as top growth.

    Since I grow in a greenhouse, I would usually hold flasks (if I could) until late winter before I would take out. The lengthening days seem to promote initiation of growth when freshly deflasked. In fact, I believe the amount of roots in flask, is not the most important factor. Getting new roots initiated within a few weeks after deflasking seems to be a better indicator of long term survival.
    Alex Shepack likes this.
  4. Ray

    Ray Orchid Iconoclast Supporting Member

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    Oak Island NC
    I have no first-hand knowledge, but might bottom heat help? I know that’s a good way to get plants reestablished after repotting.
    J E and Alex Shepack like this.