Leaves dry and crispy.

[davidwood]

Does anybody know what can be causing this on some of my leaves, they are very dry, nearly crispy[ they will crack when handled] its only on the new leaves and the smaller even turn in on themselves. I have had it before and always assumed it was the sun, but these cv's are now in the shade and its started happening again, they look very green and healthy. Could it be to much Iron or Magnesium, because I am stuck as to what it could be, and its only on 3 cv's.

[roadrunner]

David I've had the same thing you describe on and off on a few of mine too and have no idea what the cause is.  Currently I have a couple in the greenhouse, one inside the house, and one plant outside with new growth doing this. It still isn't very warm here yet so that likely isn't the cause. Hopefully Charlie will have a diagnosis.

dave

[davidwood]

Dave I am glad we can now rule out the heat. I have just noticed on mine and it may be a coincidence but 2 of the cv's where the leaves are the worst I have an explosion of buds. Saffron which is normally a bud a quarter for me has about 10,  Vin Beaujolais or Extraordinaire [ got rid of the tag thinking I would never forget] has its first ever buds, about 4. Like I said they look ever so healthy apart from this turning and crisping and its only on the new, strange, I still think I may have overdone it with something, but not sure what, come on Chris or Charlie.

[Darkhorse]

I've had this from time to time, although I can't offer any help as to the cause.  Some cvs have leaves like this naturally (Creme de la Creme, if you guys have it).  I've also noticed through washing that certain cvs have more brittle, "crunchier" leaves than others.

[helixturnhelix]

This looks like a case of "Leaf curl" which is caused by either a fungus or virus.   I would try using a fungicide and see if that improves the condition.   If not, it is likely viral and will usually clear itself up over time.  I have had this happen occasionally on one plant and it just cleared up after a growth cycle. If it does not clear up on its own, just prune the infected branch and the new growth should be fine.   

[Charlie]

This is one of those things you see with hibiscus from time to time. Usually it does not get too bad and often clears up on its own. It can have many causes - disease causing organisms as Chris described - but also insects can do this. Particularly types of mites that are microscopic in size and not visible to the naked eye. One of these is called the erinose mite and it has been a problem in Australia and Hawaii in recent years. Two others are broad mites and cyclamen mites. These are found throughout the ornamental plant world and often go misdiagnosed because they cannot be seen without a microscope. Feeding on new leaf tissue is what causes the distortions in the leaf as it grows.

I usually remove either the effected leaves or the leaves and part of the stem and dispose of them when I see this. Treatment with a miticide like Avid that works against these types of mites is also helpful. Probably oil sprays would work, too. Make sure plants showing this are not touching other plants to prevent spreading of the problem.

Charlie

[davidwood]

This is one of those things you see with hibiscus from time to time. Usually it does not get too bad and often clears up on its own. It can have many causes - disease causing organisms as Chris described - but also insects can do this. Particularly types of mites that are microscopic in size and not visible to the naked eye. One of these is called the erinose mite and it has been a problem in Australia and Hawaii in recent years. Two others are broad mites and cyclamen mites. These are found throughout the ornamental plant world and often go misdiagnosed because they cannot be seen without a microscope. Feeding on new leaf tissue is what causes the distortions in the leaf as it grows.

I usually remove either the effected leaves or the leaves and part of the stem and dispose of them when I see this. Treatment with a miticide like Avid that works against these types of mites is also helpful. Probably oil sprays would work, too. Make sure plants showing this are not touching other plants to prevent spreading of the problem.

Charlie

Thanks Charlie, what you say sounds about right, certainly the 2 I have the problem with are right next to each other, the Vin being by far the worst so have moved it. Like you also say it does seem to go away on its own eventually, but I have done as you advice and cut away the stems and leaves and gave a spray with Neem oil, I did leave a bud on the Vin as I have yet to see one.
This thing whatever it is seems to only go for certain cv's, this is about the third or fourth time and always the Vin catches it the worst.

[blupit007]

Charlie, I have this as well.  I was going to ask about it, but after looking through the forum, found this one!  Yay.  It is only on a few, and some rooted cuttings.  So I will pinch off the bad leaves.  But I was wondering.  Does Kondos not work on these mites?  I have been using it for a while with success against the spider mites, why does it not work for these mites?  OR, has it worked, but the infected leaves have not been removed so they will stay in the damaged state, (since I had no idea that it was a stupid bug that did this)?