UBC Botanical Garden Forums  

» UBC Botanical Garden


Go Back   UBC Botanical Garden Forums > Archives (no new threads) > Annuals, Biennials, Perennials, Ferns and Bulbs

Post New ThreadReply
 
Thread Tools
  #1  
Old June 30th, 2005, 12:35 PM
Laszlo Laszlo is offline
Registered Plus (3-99 posts)
 
Join Date: Jun 2005
Location: Thornhill - Toronto, GTA Area
Posts: 3
My hibiscus needs Help!

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
Reply With Quote
  #2  
Old June 30th, 2005, 01:34 PM
Michael F Michael F is offline
Plant Enthusiast (1000+ posts)
 
Join Date: Jun 2005
Location: Britain zone 8/9
Posts: 9,524
Re: My hibiscus needs Help!

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.
Reply With Quote
  #3  
Old June 30th, 2005, 01:54 PM
Eric La Fountaine's Avatar
Eric La Fountaine Eric La Fountaine is offline
UBC Botanical Garden and Centre for Plant Research
 
Join Date: Aug 2003
Location: Vancouver
Posts: 2,742
Re: My hibiscus needs Help!

Michael is probably right Laszlo. Hibiscus are very sensitive about moving or having their environments changed. Give it some time to adjust.
__________________
Eric La Fountaine
Forums Administrator
Reply With Quote
  #4  
Old June 30th, 2005, 04:12 PM
mr.shep's Avatar
mr.shep mr.shep is offline
Plant Collector/Home Gardener
 
Join Date: Mar 2004
Location: San Joaquin Valley, California
Posts: 1,394
Re: My hibiscus needs Help!

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
Reply With Quote
  #5  
Old July 1st, 2005, 12:51 PM
Laszlo Laszlo is offline
Registered Plus (3-99 posts)
 
Join Date: Jun 2005
Location: Thornhill - Toronto, GTA Area
Posts: 3
Re: My hibiscus needs Help!

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
Reply With Quote
  #6  
Old July 1st, 2005, 03:48 PM
mr.shep's Avatar
mr.shep mr.shep is offline
Plant Collector/Home Gardener
 
Join Date: Mar 2004
Location: San Joaquin Valley, California
Posts: 1,394
Re: My hibiscus needs Help!

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
Reply With Quote
  #7  
Old July 4th, 2005, 02:16 PM
Laszlo Laszlo is offline
Registered Plus (3-99 posts)
 
Join Date: Jun 2005
Location: Thornhill - Toronto, GTA Area
Posts: 3
Re: My hibiscus needs Help!

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
Reply With Quote
  #8  
Old June 18th, 2006, 03:48 PM
Chuck White Chuck White is offline
Generous Contributor (100+ posts)
 
Join Date: May 2006
Location: Florida,USA
Posts: 333
Re: My hibiscus needs Help!

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.
Reply With Quote
Post New ThreadReply

Bookmarks

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are Off
[IMG] code is Off
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
the death of a hibiscus? pinzel51 HortForum 5 June 18th, 2006 04:05 PM
Help with Tropical Hibiscus (no longer blooming) AmandaCW HortForum 2 June 18th, 2006 02:53 PM
tropical Hibiscus problems June Cunningham Indoor and Greenhouse Plants 6 September 6th, 2005 07:29 AM
Hibiscus lily HortForum 1 September 8th, 2003 09:39 AM


All times are GMT -7. The time now is 02:12 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2001-2011, University of British Columbia Botanical Garden & Centre for Plant Research