Question
QUESTION: I discovered a cottony substance on the branches, and white strands on the tips of the leaves.  There also were little white specks under the leaf.

The plant was flourishing, large, flowering, dark green leaves.  I purchased it about one year ago.

All of a sudden I noticed that the plant looked very sparse.  I saw the white specks and was able to rid the plant of that insect.  I thought all was fine.  

As I was watering the plant and walking around it, I notice white strands on the tips of the leaves, which I thought came from my sweater.  Some time later, I saw a tiny cotton ball between the twig and the leaf. I also saw this substance right were new leaves were coming in.  It looked as though it was swallowing the new upcoming leaf.

I used insect spray, I also used an insecticidal soap, and also wiped each leaf diligently with alcohol.

I could not rid the plant of this cotton.  I have been told that I may have mealy bugs.  

I finally cut the hibiscus back, and took off all the diseased leaves, unfortunately the rest fell off.

I check the plant every day and if I see a strand of cotton I remove it.

I really do not want to give up on this plant as it brought me great pleasure.

Can I save it?

Thank you for you help.

Lucille
ANSWER: Hello Lucille,

Your description does indeed sound like mealy bugs. They secrete a protective powdery wax like layer that has a consistency much like cotton.

If you haven't done so already you should get your hibiscus away from any other plants you have.

As for treatments:

You were heading in the right direction with your use of alcohol but you need to tweak it a bit. First, make sure you using 70% Isopropyl Alcohol which is just rubbing alcohol.
Using straight undiluted alcohol in large amounts can cause plant damage and may have been part of the cause of your leaf drop.

For large infestations you can make a spray out of alcohol and water. Mix about 1 quart of water for every cup of alcohol.

For smaller infestations you can simply take a cotton swab dipped in alcohol and coat the individual bugs that you see on the plant. They're good at hiding so check all the little nooks and crannies

Insecticidal soaps can also be used with the alcohol treatments to insure the pest is totally gone. The soaps can break down the waxy protective covering of the bugs making the alcohol treatments more effective.

The key here is that these treatments are done more than once over a period of time because you most likely won抰 get all the eggs in one treatment. So give it a wash in some of the soap then give it an alcohol treatment with whichever of the above methods you prefer. Now check it every one or two days and give it an alcohol treatment if needed. If after a week you still have the bugs give it another wash and start the treatments over.

Hibiscus plants are tough little buggers and it should pull through. If all the leaves are gone you should cut back a little bit on your watering. It should begin to grow new leaves on its own or you could trim back some of the stems to make it actively grow. Also, if there are any flower buds you should cut them off so the plant can put all its energy into repairing itself.

Also I should add that my second choice for the pest was the White Fly. A simple test for that is to tap the plant and see if a bunch of little white bugs start buzzing around. White flies are attracted to bright colors so an easy way to combat them is to lay down bright yellow sticky paper. I抦 95% sure that what you have is mealy bugs but I just want to cover all the bases.

Good Luck,
Justin



Hello,

Im just checking in to see how your hibiscus is doing.


---------- FOLLOW-UP ----------

QUESTION: Hi Justin, Thanks for the information. I have followed your advice, and although it looks like a dead stick, when I cut through a branch it was green.  I say a few wispy strands growing on the tips of the branches and picked it off by hand. There was one small cotton ball, but it fell into the soil.  I will try to recover it.  I would like to feed it, but I think it is not the right thing to do when a plant is in distress.  I will continue to spray it, and can only hope that I will begin to see leaves soon.  Your advice has been sound, and I do appreciate it. I would like to let you know if we succeed.

ANSWER: Hello,

Yeah, you should be careful with watering and stop feeding all together if it doesn't have any leaves. Without leaves it doesn't have anything to put that stuff to use on.

Still pulling for you,
Justin

---------- FOLLOW-UP ----------

QUESTION: Hi Justin,

Happy to report that my hibiscus "sticks" have new leaves forming.

I checked it every day and pulled off any white strings that continued to come back, used the alcohol spray, and talked to my plant.

I am so grateful for your advice and thank you for saving my plant.

I would like to ask another question?  I also purchased a yellow rhododendron (I thought I had purchased a yellow  hibiscus).  I contacted the nursery when all the leaves fell off almost immediately after planting. It did have little green buds on the branches, so all was not yet lost.  But I was afraid it would die.  I contacted the nursery and was told that this is perfectly normal and in the spring the buds would open, and the plant would bloom.  But this hasn't been the case. The green buds died over the winter, and the plant certainly looks dead.  I cut through a few branches, and while the inside of the branches wasn't exactly green, it was more like yellow, but, then again, it wasn't brown. I am not sure if it is dying.  Does this little plant have a chance?
Thank you so much, Justin.  Maybe you can do your magic again.  Lucille

Answer
Hello again,
Lucille

Im sorry i don't know much about Rhododendron.

But these people do

http://www.ubcbotanicalgarden.org/forums/forumdisplay.php?f=131

They move kind of slow so you'll want to get as much info into your first question as you can. Where it was planted(what side of the house), when it was planted, what kind of soil it was planted in, and the information in your question to me. Also, if possible you should get them a picture.

I've been a member there for a long time and when i get stumped with one of my plants i go to them. I'm very rarely let down. It only takes a few minutes to register and you get info from other gardeners and researchers/students at the university.

Another route would be to go back the the nursery again and ask them. If you complain enough you might even get a new one.  :-)

Good luck,
Justin