Jacaranda

Discussion in 'Plant Propagation' started by malcolm197, Mar 16, 2006.

  1. malcolm197

    malcolm197 Active Member

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    Last year I purchased some Jacaranda seeds in Madeira. I have duly sown these in a heated ( constant temperature) propagator, in an unheated but frost-free conservatory ( I do not have a greenhouse). However they refuse to germinate - but there is no sign of any fungus,rot or mould on the surface of the compost. Does anyone have any idea how to "kickstart" these seeds or should I throw them out and start again?
    My gut feeling is that the propagator is not warm enough due to the low "backgound" temperature, but not having tried to start tropical shrubs before I really have no idea about what I am doing wrong ( although I once succeeded germinating but not growing on a carob seed). I have had no problems growing higher-temperature "soft-tissue" plants like impatiens,begonias and the like under the same conditions. I keep the compost damp,but not wet, and I use warm ( well not cold) water to irrigate so as not to inhibit germination.
    ....or is it simply that Jacaranda is "difficult" ?
    How long should I leave it before abandoning the attempt, or should I just wait until the ambient temperature increases - it is unseasonably cold at the moment.
    Any assistance gratefully received.
    Regards from UK
    Malcolm
     
  2. Eric La Fountaine

    Eric La Fountaine Contributor UBC Botanical Garden Forums Administrator Forums Moderator 10 Years

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    They are supposed to be relatively easy to germinate (I have no personal experience though.) Here is a link to a Brazilian study that tested various conditions for the tree's germination. They found the ideal temp. for germination of jacaranda to be 25°C. They briefly mention light, but I noticed that other sites pointed out that light was necessary for germination. Apparently they do not germinate in the forest unless the canopy is cleared.

    http://www.scielo.br/scielo.php?pid=S1516-89132004000500014&script=sci_arttext

    Good luck,
     
  3. bcgift52

    bcgift52 Active Member

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    I soaked the seed in warm water for 24 hours, sowed and germinated 5 out of 6 by
    the 8th day. I sowed indoors. If no bumps showing on the surface yet, I'd dig some out and try a soak.
     
  4. malcolm197

    malcolm197 Active Member

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    Thanks.
    The scientific bit is a bit over my head, but I guess it means that if I expose the seeds to light on the surface of the compost they might stand more chance of germinating if the other conditions i.e. water and temperature are less than ideal.
    If the seeds are still OK I will soak them overnight ( and possibly scarify ) then bury half and expose the other half and see what happens. If this doesn't work I will use the old standby and put them in the airing cupboard for a week! After all at this stage what do I have to lose?
    I won't be able to grow them outside anyway in this country, but I thought I might try to get one survivor as a large indoor pot plant.
    As I mentioned I did manage to germinate a Carob once but it succombed to red spider mite when it was about 3 inches tall.
    I will post the results - in the interests of science!!
    Thanks again
    Malcolm
     
  5. malcolm197

    malcolm197 Active Member

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    Sad news. I checked the seeds. No rot or mould - the seeds have just "dissolved" into the host compost leaving not a trace! 1 Euro down the pan!!
    Malcolm
     
  6. oscar

    oscar Active Member

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    The seed might not have been viable in the first place........dont give up, from what bcgift52 and Eric say, you stand a much better chance next time.
     

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