My hibiscus needs Help!

Discussion in 'Annuals, Biennials, Perennials, Ferns and Bulbs' started by Laszlo, Jun 30, 2005.

  1. Laszlo

    Laszlo Member

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    I bought a hibiscus plant in June this year form home depot; it is a braided tropical hibiscus - with beautiful yellow flowers. I have replanted it and keep it outside. it gets direct sun till about 1-1:30 pm. After about a day or two it developed yellow leaves. These leaves have black spots on the back. The poor plant is loosing its leaves fast. A garden centre, where I took some of the yellow leaves, diagnosed the problem as 'spider mites' and sold me "Safer's End-All". This product, applied as directed, does not seem to help the problem.
    Please help. I really love this plant.

    Thanks
    Laszlo
     
  2. Michael F

    Michael F Esteemed Contributor Forums Moderator 10 Years of Activity

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    Had it been inside when you bought it?

    If yes, then it is probably suffering from sunburn. Glass/plastic cuts out UV light, and any indoor plant moved outside into more than an hour or two of sun on its first day will get burnt - just like people, they need slow acclimatisation over a few days to adapt to direct outdoor sun. It should put out some new leaves fairly soon, and these will be naturally adapted to full sun.
     
  3. Eric La Fountaine

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

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    Michael is probably right Laszlo. Hibiscus are very sensitive about moving or having their environments changed. Give it some time to adjust.
     
  4. mr.shep

    mr.shep Well-Known Member 10 Years of Activity

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    There are a few avenues of thought in that the
    plant was originally grown in a greenhouse
    and given ample light of which the plant will
    show signs of being unhappy once the hours
    of light have been reduced. The hibiscus can
    go into shock because of the lack of light, much
    like a florist Azalea can when we get one and
    do not fertilize it every time we water it.

    There is also the fact that too much water can
    also cause the leaves to turn a golden color,
    shrivel up and fall off. More leaves will do
    this in rapid fashion than a sunburn as the
    burning usually does not affect a large series
    of leaves all at once, surely not likely in
    Toronto yet. Here is a different matter but
    even then these hibiscus can handle 100
    degree temperatures coming from shade to
    sun as long as we give them enough water.
    The leaves will show signs of wilting before
    they start to burn up. The plant will tell you
    when the leaves are at risk of burning.

    The black specks on the undersides of the
    leaves is not due to sunburn. We will see
    that here when there is not enough light
    given to the plant and that could be the
    result of bringing the plant in from a
    greenhouse into a shaded area to be sold
    to you.

    You may want to read the material from
    this link as you will want to bring this
    plant indoors for the Winter. We have
    to bring them indoors even here or they
    will die outright once the temps get around
    28 degrees outdoors. Tropical hibiscus
    can handle heat much better than they can
    handle cold.

    http://www.trop-hibiscus.com/gindr.html

    Jim
     
  5. Laszlo

    Laszlo Member

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    Thank you all for the suggestions. Here are some other facts:
    1. It is the large leaves which turn yellow and shrivel.
    2. There is a heat wave in Toronto - we had 30+ degrees (C) for about a week.

    It is possible that I overwatered this plant. How often should I water it? (We do have a moisture meter.)

    Kind Regards
    Laszlo
     
  6. mr.shep

    mr.shep Well-Known Member 10 Years of Activity

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    I was not saying that what Michael and
    Eric wrote could not be the problem as
    it could be. We have no idea as to what
    the plant looked like when you bought it,
    how long it had been in shade and how it
    looks now.

    In temperate areas these can be watered
    every day with sprinklers but they will not
    like deep watering every day. In Florida
    and even in Hawaii they can get watered
    every day. One by applied water and the
    other by rainfall and mist. I would think
    that a good watering twice a week will be
    ample until the temperatures get real warm.
    A lot depends on if you planted the hibiscus
    in soil, in potting soil or did you use a mix
    of soil and potting soil. With soil twice a
    week should be plenty or every third day if
    it is real hot and the leaves start to droop.
    If the plant was planted in straight potting
    soil then you may have to water more often.
    The leaves will go from drooping to a
    noticeable wilt when the plant feels it has
    gone long enough without water.

    Jim
     
  7. Laszlo

    Laszlo Member

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    Hi Jim;

    Thanks again - I used an 'all purpose potting soil' under and around the root structure and a 14" pot. I also made sure the pot has good drainage. I think now I got the idea re. watering.

    She (must be!) still looses leaves. Some new some old. The problem starts with a yellow area in the center area of the leaf - with the black spots under the yellow area. Adventually the whole leaf turns yellow, shrivels and drops. There are also holes in some leafs - I think this is something new.

    The good news is; based on some digital pictures, I got my money back from Home Depot. Still, I would like to keep the plant. We love the huge yellow flowers.

    Regards
    Laszlo
     
  8. Chuck White

    Chuck White Active Member

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    Laszlo: During the summer growing period, as new growth is added to the branches of most hibiscus, so will the bottom leaves on that branch begin to yellow and fall off. A hibiscus will not maintain the 'full leaf' look of, for example, a privet. It is the nature of the beast to lose leaves through-out the growing season (year-round here in Florida). 'Though a hibiscus will grow in every thing from sand to clay, they are very happy if the soil has good drainage, i.e. a high organic content. Seems your guy is at your mercy 'cause it is in a pot. Customarily, for a planted hibiscus outdoors, I would recommend only 1 inch of water per week. Hibiscus like to have damp, not wet feet. It doesn't take much over-watering to have the plant develop root rot. Your hibiscus also wants a Ph of from 5.5 to 6.5. They are acid lovers.
    Judicious use of Ironite (ferrous sulphate) or Magnesium sulphate (Epsom salts) will green the leaves as you may not have seen before. OR, use both. The sulphate will, of course, be converted by bacteria to sulphuric acid , which, for a limited time, will increase the acidity in your soil. This is especially good if your soil is on the alkaline side of 7.0 Ph.
    Your concern has been leaf drop. Wait until you experience BUD drop. Yes, they do that, too. The U. of Florida has a classic response for that. It is: too much water, not enough water, too much fertilizer, not enough fertilizer! There is no well understood reason for hibiscus to drop their buds, but at some point in time or another they do. Usually, it is no more than just an" aw shucks". New buds are coming all the time if the plant is happy.
    Just some added thoughts for you to put in the hopper. Good luck.
     

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