it has to hit green tissue..

it has no impact on bark or soil

dont you think that week long heat wave might be your source of trouble...

i hear it was a wee mite hot in NY ... all the way across lake erie to me in adrian mi ...

post some pix if you want me to consider changing my mind ... otherwise i dont think the RU had anything to do with it...

ken

Some thin barked trees can take up the R-U through the bark. Peaches are one that comes to mind. Round-Up should never be sprayed on anything you don't want to kill.

What size trees are we talking about? Are the trunks, where the RoundUp was sprayed, still green (rather than aged bark)? Was the wind blowing when the chemical was applied?.....We need more info. Otherwise, what Ken said.

Another thread has me thinking...if they are fu fu grafted plants that sucker and round up gets on the suckers near the base then that is obviously bad news for the tree.

Two known episodes of established tree plantings going south after glyphosate was applied to the soil only are described by Carl E Whitcomb in his book Establishment and Maintenance of Landscape Plants.

Wow! Thanks for all the quick responses! I moved here 7 years ago and most of the trees in my yard were planted 5-7 years ago. My 5 acres were in crops back then. Now, I keep 2 acres as lawn and a farmer plants hay on the rest. Two trees are Red Maples and only one was sprayed. One is an October Glory and I don't recall which tree it is. The untreated tree looks fine but the sprayed tree has some droopy and shriveled leaves. The maple seeds are in very poor condition on the affected trees. Two are Sugar Maples, both treated, and one has never flourished. It has been suggested that these trees don't like really wet areas and I did plant them near each other next to a drainage ditch. The scrawny tree is looking terrible. One Maple that has maroon leaves, not a Japanese, is fine. The Thornless Honey Locust is probably OK with some yellowing. My Prairie Fire crabapples were sprayed and only one looks distressed. Another white flowering crabapple is affected. I planted a very small hydrangea last year; it was sprayed and is fine. My purple plum tree is also fine. The Tulip tree was sprayed and is OK. I have 4 Redbuds and 3 were sprayed. The sprayed trees look a little pale. As for the recent weather, this summer in the Syracuse area has been terrible. My 5 acres are usually soggy after heavy rains and we have had unrelenting downpours often this year. Late spring was very cold and then we have had several periods of record or near record high temperatures. Terrible heat for long periods could also be a factor but, as I said, my land is on the wet side. I have had a lot of difficulty cutting the grass because the lawn is so wet the garden tractor keeps getting bound up with clots of muddy grass. I had to water a raised flower bed and the vegetables only once this year, after the initial planting. Last year we had a severe frost just as the trees were leafing out and there was severe leaf death during the spring. However, all the trees grew new leaves and did well. I really hope, for whatever reason some of my trees are looking poorly, that they will bounce back next year. Thanks again for the information.

Roundup is not your issue IMHO. Wet appears to be your issue, Droppy leaves are not the symptom of herbicide damage, but damage to the root systems from excessive water will produce the symptoms you describe. That and perhaps the farmer used broadleaf herbicide. The owner of the horse pasture behind my house was out spraying on the windiest day of the spring this year. I knew he was spraying broadleaf herbicide, and getting very close to the fenceline. So I got a chair and sat where he had a very clear view of me with camera in hand (also very visible). suddenly, he wasn't spraying nearly as close to the fence. I hosed down our plants near the fenceline when he was done, and there were no symptoms. But I still think it's too wet. .

JMHO
Arktrees

The maple seeds are in very poor condition on the affected trees.

==>> i dont understand how your maples are still holding seed pods in july .... which i making me wonder if they are maples???

ken

Normally, absorbing tree roots are not right at the soil's surface. This is largely because the surface dries out frequently. When glyphosate/RoundUp is properly applied only a light mist will make it to the soil's surface and there will not be enough liquid to soak down into the soil. The glyphosate quickly bonds to soil particles and so does not normally reach a tree's roots.

I can think of two reasons that glyphosate might reach absorbing roots, even if they are at a normal distance below the surface. One is if a large amount of the chemical is applied (misuse) and soaks down into the soil. A second is if the chemical is mixed too heavily (misuse, at least in this case) and plants surrounding the tree are able to translocate the chemical down into the soil where tree roots, growing very close to the other plant's roots, are exposed to the excess chemical. Normally there isn't much qlyphosate exuded by roots, but it has been know to happen with heavy applications.

Other potential exposure issues might occur with green/young bark, fresh wounds, or windy conditions.

None of this is to say that glyphosate is the problem in this case.

There really are seeds still on the Sugar Maples. The one that is almost dead has seeds that are brown and shriveled, and I do know that these are really maples. The robust tree has seeds in which the actual seed area is green and very swollen and the "wings" are yellow to red. The Bloodgood, Crimson King, October Glory, Sunset Red and the Norway maples all do not have any seeds still attached. It has been an unusual spring and summer as far as temperature and rainfall go. Also, I have two strengths of Roundup in the garage and the cleaning lady/gardener may not have noticed and actually used the wrong strength when mixing chemicals. I'm 69 and don't have time to replant all my trees and see them grow to maturity so I hope the sickly trees come back healthy next year. I appreciate all the technical advice and information.

I made a mistake. The Norway is located inside the fenced dog acre and when I was just out there I noted it is laden with seeds. Everything about the tree looks healthy and it wasn't sprayed.