stumped #2

ATH

Well-Known Member
here is Stumped #1

So...this guy was fighting cancer all last year and let the landscape get out of hand. To address that, he mixed up some generic Roundup (glyphosate) and went to down on the weeds in all of the planting beds. This spring several things did not leaf out:
*Crabapple
*Red maple
*Burning bush
*Weeping cherry

But in the same beds, evergreens are dong OK - boxwood and birdsnest spruce things.

He swears he didn't use anything but glyphosate...showed me the jug (Glystar brand). If he showed me dicamba or 2, 4-D, I think it would make more sense.

The Crabapple, maple, and burning bushes have a few starts of leaves looking like they want to push out and the twigs are still green. I told him to give them until the end of the month and if they aren't out by then to remove them.

So why did glyphosate do this (or, what else could it have been???)

There is a bed between his and the neighbor's. His magnolia is stunted, the neighbor's is not...at all - the canopies overlap by a couple of inches???

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colb

Well-Known Member
Glyphosate can "burn" leaves off without killing the tree. Before the air potato beetle release, I sprayed air potato with 1% terrestrial formulation, basically broadcast because the air potato was so thick. It would kill the tree leaves along with the air potato, but the trees would then resprout leaves and go on their merry ways. Hth...
 
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colb

Well-Known Member
Is there an adjuvant in the formulation? Usually homeowners get a jug that isn't pure glyphosate - it's mixed with a leaf penetrant/surfactant. The adjuvant can burn leaves at high concentration. Again, it doesn't necessarily go systemic and allows the plant to come back...

Both possibilities are concentration-dependent. Professional applicators put out spray at vastly different rates due to individual idiosyncrasies. I imagine homeowners are *way* more disparate. If he applied enough glyphosate or adjuvant he could have killed any of those plants.

I outlined a treatment for a chemist once. Came back months later, noticed scorched earth, and asked after the rate that was applied - way off! About 5x more than label rate from what was described. Fortunately, there was no off target damage... just a really hard hit to some grape vines!
 
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ATH

Well-Known Member
He sprayed last fall (I think he said with leaf on, but I honestly don't recall that we had that specific conversation). Said he only sprayed the ground - not over the tree canopy - so I get what you are saying about knocking the leaves off...but would that fit here?

Note the weeds that are coming up quite well now, so it is not like he sterilized the soil.

He doesn't remember the concentration he used, but I'm guessing it was heavy...but not like pure product. The tank was a 35 gallon tank. I didn't think to ask how many times he filled it or if he used the jug anywhere besides that tank. There was maybe a gallon left in the 2.5 gallon jug. So if he put 6-7 quarts in 35 gallons that is right around 5%. Heavy, but not off label heavy. (Used a new tank so I don't think cross contamination was the issue.)

The most puzzling is how did the little spruce things not get it? They would have been far more subject to overspray.

One theory: did he spray enough on the trunks of the trees (thin bark) to have some impact???
 

JD3000

Most well-known member
That's what I assumed but those dwarf conifers should show damage too I would think.
 
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colb

Well-Known Member
You know, on one hand it's a puzzle - how or by what path did shit go down? On the other hand, shit definitely went down, and to a great extent. Can you imagine any other cause for this? And what is a 35 gallon rig doing in a small space? And 1.5 gallons is a lot in a small space.
 

ATH

Well-Known Member
I agree...they do have a fair amount of space - but it should not have taken more than 10 gal of mix. He is taking the blame on himself. His question for me was "will they live?".

I doubt it, but like I said, lets see what those tiny leaves to. We aren't replanting until fall anyway, so no rush yank out something that might push out.

I'm just personally puzzled how glyphosate did this...especially with a few that escaped the nuclear attack.
 

Nish

Well-Known Member
It looks like there may be some soil erosion there. My theory: the applicator drenched the ground with 5% glyphosate but was a bit more careful when spraying around the evergreen shrubs. The trees/shrubs were damaged by having their exposed feeder roots drenched with the glyphosate solution.

Thanks for posting this. Fears of errant herbicide application keep me up at night.
 
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