If your life lacks drama, just use your herbicide sprayer (empty but not cleaned out) to spray insecticidal soap on ALL your apple trees. I figured out what I’d done and ten minutes later ran around madly hosing down my small apple trees. Will know in a few days.
Hoping the neem I sprayed a few days ago might protect the leaves a bit from Roundup.
True confessions.
I get to do a taste test before I spray anything. Whenever I fill up the tank with water, it spills right into my face. 
I guess God has his ways of guiding us all 
I write on my sprayers, buckets, empty gallon water bottles, etc of what they have had in them.
Good luck, you should be OK. Sometimes I spray the invasive trees at the back of my property with
Roundup on purpose and it wont even kill them.
I have two tanks - one for herbacide, and one for insecticides and foliar fertilizers. Both are clearly labeled. Never shall the twain be combined at my house. I am just too forgetful, and that could spell disaster here. Crossing my fingers for you!! Very scary.
Good idea labelling everything. Better late than never.
I have three tanks - one for herbacide (marked), one for organic (marked), and one unmarked and unused because I don’t remember what it was used for. Bill
Hah, hahaha! OMG, that sounds just like something I would do, Bill. That’s too funny. Oh dear. The challenge is, if it was used for herbicides, you can’t use it for anything else, really. How frutrating. Funny, but still, frustrating. 
speaking of heartburn, insecticides, and fertilizers:
malathion insecticide analogs may cause severe heartburn, due to parasympathetic stimulation, but an antidote could be sitting next to the insecticide container-- agricultural lime(calcium carbonate, which is in fact, tums).
Oh no Hambone!!! 
My ground clear sprayer has a skull drawn on it, with GLYPHOSATE in red, angry sharpie.
Oh dear. DO keep us posted and I hope it was dilute enough not to cause an issue.
I drew the skull because I feared EXACTLY what happened to you! Its an easy enough mistake to make.
Thanks everybody for your concern. Will report back in a few days.
I just never mix my chemicals. I have my orchard sprayers which only get fungicide and insecticide. I keep my herbicides in separate sprayers.
In the prior decade I sold a pallet of palm tree fertilizer to a hotel/resort under construction in Las Vegas. Three weeks after delivery I started getting bitter complaints. So I drove out there and talked with the landscape maintenance workers. They showed me their equipment, their tanks, and very proud they had saved money and reused them after spraying the entire grounds with herbicide. I took a picture of the empty drums of glyphosate and sent it to the management. They apologized, bought new foliage, new equipment, and another pallet of fertilizer. Happy as peaches every since 
just realized, have limited myself to growing my moniker and other feasibly-organically-grown fruits and vegies, that have not used nor purchased any insecticides/herbicides for a decade now.
feels hippie good, will have to say!
Must be great to have such low pest pressure!
Whatever gets spayed in the first few minutes will be most affected due to the full strength mix that might be left in the pump and plumbing. The leftover in the tank will get diluted, so I think that would be less of an issue. If you take time to drain the complete system and wash it out well, you should be able to reuse it for just about anything. It’s good to fully flush the system anyhow, since debris buildup will clog the nozzle more frequently.
Plastic is somewhat porous. Most liquid herbicides will partially penetrate plastic containers and will be leached out again in the presence of an acidic nutrient solution.
So far so good, trees look ok. Have searched but failed to find an organic substitute for Roundup to kill wire-grass that grows like kudzu in my mulch. Am organic otherwise. Friends have tried vinegar but apparently doesn’t touch wire grass. Any ideas?
Regular store-bought vinegar (5% acetic acid or 50 grain) bought off the store shelf won’t work very well as an herbicide for any weed. What you need to use is pickling vinegar (10% acetic acid), and you need to apply it several times. A hot day helps. Not sure how well it will work on wire grass, though, glad I don’t have that in my yard, it sounds pretty tough to get rid of.
