I am a condo dweller and am trying to be a good samaritan taking care of the rhododendrons planted in our complex. They seem to be sorely negelected. I'm watering them and notice new growth on one is coming out shriveled and wrinkled. Is this a pest or a fungus and how to deal with it? Leaves on another are spotted brown. Please advise me. Thanks
Brown spots could be mildew, shriveling might be drought injury. When the plant gets too far dried out before being brought back with watering the new growth may have died in the meantime.
hi any chance of a pic Are they close to the run off of a Cedar or Pine roof/siding Has your condo been worked on for the leaky condo type stuff/ and a new stucco been done in the last 2 years Also check out around the drip zone of these plant and make sure that plastic was not used as a weed barrier. It may be 2 to 6 inches down below the surface. Regards Doug
Thanks for your response. I hope this gives you a passable image. I also noticed little tiny white dots on many leaves on the same bush. None of the condo conditions queried in a previous response are true for my condo. Thank you, Mama Cass
Hey Mama Cass, If you have an image you could attach it. Here is the link to the How To: http://www.botanicalgarden.ubc.ca/forums/showthread.php?t=725 Welcome to the forums,
When shriveled new growth appears here, it's due to a fly that lays her eggs in the buds. Spraying with Cygon just as the buds begin to open and then 3 weeks later gives total control here. I learned this from Ted Richardson, a wholesale Rhododendron grower in the NC mountains. It's been effective for the last 15 years.
Thank you. I will give this a try, although the new growth is well out now and no longer just a new bud. Mama Cass
Probably too late for this year then, but it may cut down the infestation next season. Give it a whirl nest year and let me know how well it works. Cygon has been removed here while they give it a new name and double the price. Perhaps other systemic insectacides will work as well, but I've only had experience with Cygon.
Hi, I apologize to all involved in this thread (and particularly Mama Cass) - I've had these photographs from the original poster sitting in my inbox for a while - I think they arrived while I was on vacation last August, and I'm only now getting to them as I attempt to slim and trim my 350+ email inbox before going on vacation again. Again, my apologies.
Don't know about scattered puckery leaves, but new growth with white dots in summer is insects. Look closely for bugs, like aphids. The notches in the leaves in your pictures are weevil damage.
Shriveled new growth is usually the result of a fly that lays her eggs in the buds. Cygon 2E applied just as the buds are about to burst cures the problem. I got this from a commercial grower in the NC mountains, and it's worked very ewll. Problem is, Cygon 2E has been removed from the US and Canadian markets. I understand that Merit is the preferred replacement, but I have no experience with it yet.
Are these Rhodos planted on a slope? under the building's eves? If they dry out in our dry summers, this has a dramatic effect on their growth cycle, the weevils have had their feast and will continue to do so. During the spring and summer nights, spread out a white tarp under the plant, and at 4 am, check them out, shake the branches and see how many of those weevils you have harvested! Try this on a weekly night ritual, it could only help the plants and give you an early start to your day! Try pouring cold tea baths on the new growth, the acid may be a natural cheat to arresting the mildew...well at least it,s woth a try and you can do this after your cup of tea in the morning!:)