Can you post pictures of some of the commonest weeds in your yard? Several plants smell peppery or oniony. (I've never smelled pepper spray). Garlic mustard would be one to start with.

I'm going post a few pictures of the weeds in the area where I notice it the most. I couldn't really match it up with the garlic mustard, but lol I don't have much of an eye for this!

Thanks for the quick response

Another one

This one too

the last one

I can't make out any individual plants in the top picture. In the second there are only violets and chickweed, neither of which has any peppery chemical smell. There's some sort of Ranunculus in the mix too. I can't see anything which is definitely peppery.

You could crawl around the yard a bit and tear bits of different plant leaves and sniff??? Or has your neighbour perhaps used some sort of spray or powder to deter animals? Pepper dust is used to keep cats out of garden beds. No further ideas, I'm afraid.

I had typed into google "my eyes are burning like pepper in my eyes while mowing lawn and came to this page. This man's weeds in his lawn look just like mine. My skin even begins to burn when I sweat. I was almost doubled over with pain due to the pepper spray feeling. My nostrils were on fire and I had burning in my throat. I see bugle weed in there like mine and the second pic and the last pic have a lot of what I have where it began to burn. It is something in there. I'm still on fire more than 30 minutes after being done. It is a horrific feeling.

The pictures he posted do not have enough detail for the individual plants to be identified. If you could take pictures, close-ups, of the different kinds of weeds you're dealing with, and post them to the Name That Plant forum here on Gardenweb, you will get answers. But we really need better, closer, pictures than these. And you might want to talk to your doctor, because it sounds like you are having a really, really bad allergic reaction to something here, and that can be dangerous.

This is my second year experiencing this- during mowing I must be cutting some weeds which are like a ground cover which give off an ammonia like effect,,causing my eyes to water, nose to run, almost to the point of a headache. Only occurs in the spring- after the fescue comes on strong, these weeds go away and I am not bothered by it. I cut 3 acres and by the end of it I am crying and wheezing and can barely keep,my eyes open due to the burning sensations. Anyone had the same experiences?

I'm having the same issue here in NC. I'm thinking it's the Carolina geranium weed when cut.

This just happened to me as well. I have four acres that I mow. I was mowing the west part of the lawn which is heavy on a variety of weeds. It felt like I was cutting onions without any distinguishable oder ( very painful for the eyes). No idea what weed is causing this??

Just found this. It's horrible. It burns the eyes and throat so bad! I thought my son was just trying to get out of cutting the grass. I went and took over and it was horrendous!! What the h*** is it?!!

Looking at the first photo that you posted, my brain says you have something that is what I just had a problem with. I have this vine that took over a piece of privacy fence and down onto the ground. After leaving it alone for a couple years, it is now a nuisance and needs to be taken out. I decided to start by mowing the ground part first. When I did, I suddenly felt like my throat was on FIRE. I had to stop working and days later my throat still hurts. I think I have found the culprit's name: Clematis terniflora. I found a description of the plant that all parts of it are poisonous if ingested and can cause allergic reactions /skin irritations. https://en.wikipedia.org/wiki/Clematis_terniflora. It's in the rununculales ( buttercup) order, so the common thread in that order seems to be the pepper spray effect. :/

I just had the same act experience and I have never had this experience in my life. It's horrible. So how do we get rid of this thing?

It would appear that some have a much more severe reaction to buttercups than others. Maybe taking a benadryl or 2 before you mow might alleviate the problem somewhat. The plant spreads across the ground, and roots along the stems forming a colony. Best way to deal with it would be to rip out as much above ground growth as possible, to prevent any further spreading, and then use a weed killer, and hand pulling to completely eradicate it.

I've been landscaping for 3+ years & the ONLY thing I can tell you jdrcorp is that it has no name, it's evil & literally the only thing that helps is a face respirator. I'm serious, whatever it is hurts my skin, my face, burns my eyes intensely. I was doing an overgrown lawn yesterday & I had to stop six times. It was overwhelming.

I've been doing research trying to find a name for it. It's here in Virginia, everywhere. & once you cut it & it's in the air it releases an overwhelming chemical. I wish I new exactly what plant it was. If anyone finds out let me know!

We just ran into this. It is brutal! Out of know where you eyes start burning and you can't see. Your nose does not stop running, It took us two bottles of water poured directly into our eye and the we still couldn't keep them open for almost 30 min. It has subsided but is still burning, but I can see. We had what looked to be a vine in the middle of the yard. But we also had some long stringy stems that were cut up after it was mowed. I think they were the culprit since it was much more intense where they were. I will take pictures next time. It sucks

p.s. I am in Richmond, VA

Article on irritants in buttercups

Protoanemonin info from Wikipedia

The Wikipedia article says it's released when the plant is 'wounded or macerated', i.e. mowed. The one picture posted above looks like one of the little weedy buttercups, and one of the other posters mentioned Clematis, which is also mentioned in the article. I didn't know about this and don't know that this is actually the problem, but it sounds like it could be.

I came home and noticed a bunch of weeds growing in the rocks In a walkway. I quickly pulled some out with my bare hands, not really thinking about it. I must have rubbed my eye and within minutes my eye was on fire. My tongue was also stinging. I started with eye drops and ended up in the shower trying to rinse out my eye. Then I stood in front of a fan trying to air it out. More drops. It was awful and burned for 2 hours before letting up. My nose was also running. I imagine this is what pepper spray must be like or maybe this was worse. I almost went to ER. When I woke up the next morning my eye was extremely swollen and red. Here’s a picture of them but I don’t know what they are. Any ideas? This is in the Northern California coastal area.

That's Euphorbia peplus. The white milky sap of Euphorbias is irritant to many people although I've pulled it for years with no effects.

I've got something similar in my backyard. These weeds only burn my eyes when mowing, but they burn strong. I have 2 neighboring lawns, so I believe this has come from either yard, plus a tree was once where the majority of these weeds are now. Any remedies for killing these weeds? I've killed other vegetation in my yard as seen in the pictures.

Please post a close up and geographical location if you want your plant identified.

These weeds burn eyes like pepper spray when mowed. They are present in one yard but not adjacent yards. No blooms but perhaps mowing has prevented bloom development. The leaves visible are all same type of plant. The leaves have light zonation.

It looks like a Clematis vine/bush, and I can't imagine them ever being irritating, but it seems a few people are allergic to them.

https://forum.gardenersworld.com/discussion/994698/clematis-allergy

Yes. Last picture is a Clematis. The white splashes are typical of C terniflora.

The irritation is present after mowing the plant before it has ever bloomed. No flowers or pollen from plant present.

Leaves can cause allergic reactions, not only pollen. Especially if bashed up and releasing their various chemicals.

OMG yes... Did you find out what it was please... Its a dark green honey plant... That burns your eyes and nose

Is this the same thing you

Hello. I mow a golf course which had abundance of eucalyptus trees. When the flowers drop to the ground. This dust in the air stings my eye emmencly.

Hello. I mow a golf course which had abundance of eucalyptus trees. When the flowers drop to the ground. This dust in the air stings my eye emmencly.

Same problem here in Southern Illinois. It has even spread more this year and has taken over my entire back yard. The burn when you mow to your eyes and nose is terrible and i also can't find any information on this week either. I was told burn it out but my yard is large and i live in a residential area. Just wish i could kill it somehow.

I am now spraying RM43 in spots, and I have grass that I wanted removed dying already, about 10 days in. Awaiting results on the weeds in the pictures. https://www.raganandmassey.com/rm43.html

I just moved to Oklahoma last fall. every time I’ve mown this year my eyes have been on fire. first time I just stuck it out. and I couldn’t read for about 3 days afterwards. I mow 3 acres so I’ve been using a full face shield and stopping often to rinse my eyes. Now I’ve noticed when I go out side my eyes start burning right away. Never experienced this before?

I've had this exact same issue with these vines in Oklahoma, if you mow over them it's like they are releasing a toxin in the area that blinds and chokes you, I finally managed to get rid of it, use gloves and a machete or gardening sheers, it's a long process but doing it this way I was able to pull it all from the side of my house bag it up and get rid of it then finally managed to mow without any problem.

Without pictures there is no way of knowing if people are dealing with the same or different plants and no way of identifying them.

I get the burning eyes mouth and nose also when cutting part of my yard. I took a picture and it is some type of Autumn clamatis vine. I read about it and when cut it is toxic.

I have these same issues with my lawn and figured it come from the chemicals that the government be spraying from the planes it trying to damage the good soil it comes from the spraying from the planes

Not sure why the website wouldn't let me type anything from my phone, but here I am. I am in Oklahoma as well and this vine is what causes the issue. The Plant ID calls it Clematis Chinesis. I can find all sorts of uses in medicines but cannot find anything stating that it causes what most of us are experiencing. I feel horrible as I am in a residential neighbor hood and my dogs run around the back yard, but the grass is so high because this vine is everywhere. When I mow, it is like someone poured straight alcohol into my eyes that they won't even open, My Nose starting dripping like a leaky faucet and My lungs close up.

Highly unlikely to be Clematis chinensis which is not a US native and is not particularly commonly grown. Much more likely to be C. terniflora. See above. I very much doubt a plant app can tell one Clematis from another by leaves alone.