Poison ivy : copper and sulfur for knockback?


#21

Yup, I mow a fair amount of it too. Last year I learned a painful lesson though. PI oil stays on metal (like mower decks and blades) for quite awhile. I got a heck of a case of PI after changing my mower blades. Be careful


#22

Full strength is not what you need! Not more then double strength. Full strength kills leaves immediately - they do not have time to send the poison to the roots. And this is what you need to kill it. You need to be patient with PI.


#23

I’ve sprayed PI with 2oz. 41% gly concentrate per gallon water, 4 oz. 41% gly concentrate per gallon water, and 6 oz. 41% gly concentrate per gallon water. All yielded the same, unsuccessful results. PI died back, appeared dead, then resprouted from the roots and looked perfectly healthy again.

I can spray PI once with Crossbow at 2 oz. per gallon water and it is D…E…A…D…and it doesn’t resprout.


#24

The poison ivy spray concentrate made by Bayer seems to be the best. Better than straight 2-4-d,


#25

For a Roundup substitute I prefer the Glyphosate by Bonide.

Works best in a side by side trial I did 2 years ago…with Roundup, Sprectracide, and the Ace Hardware product. And Bonide’s product.


#26

Really? Would not have expected that.
Never know really effects til u look for yrself


#27

In addition to what others have noted about specific herbicides, there is some information in the UC IPM page on the timing of application.


#28

Good to know. Thanks Vohd i bookmarked that page


#29

I had a bad problem with poison ivy at my place when I first moved here. What seemed to really help kill it was adding some dollar store dish detergent to the herbicide mix as a surfactant. I think it helped break down the oily coating on the PI leaves and let more of the herbicide get into the plant.


#30

I forgot to mention CROSSBOW in my post…old age I reckon.
Crossbow works just as well as the Bayer poison ivy product.
Both are way, way, way ahead of Roundup for poison ivy.


#31

I’ve been using 41% glypshosate 2 oz per gal for the last 10 yrs with success. That may be because I’m only killing PI plants less than 1 yr old that have been seeded by birds.


#32

Oh nice. I like that idea. Thanks


#33

Ideally after i kill the current ocean i have thats where i will be at too.


#34

Ty for the info on comparisons BlueBerry :relaxed: