Neighbor sprayed my plants...

No proof of it but I'm convinced he did.
Killed my willow starts,  my crabapple tree and tried the peach tree.
I'm building a fence,  but he will probably spray anything he can reach.
My question,  should I seek out roundup ready crops and weeds?
If nothing wilts,  he will probably stop spraying.
If I can find something tall,  it will block more poison.
If it sucks up the poison,  I could discard the plants in the trash.
I will be putting our shed next to that property line,  and bunches of mulch as well.

Any ideas on other mitigating this threat,  or plants to use would be welcome.

Pretty sure that's illegal.  Check with your county agricultural department.  Why on earth is he trying to kill your plants?

Definitely a TALL fence, as tall as you can make it.  And NO on the "Roundup Ready" stuff.

One thing you can do to remediate the areas he's already sprayed is with mycellium.  You can probably purchase it at a garden center near you.  If nothing else, get some mushrooms from the grocery store and bury them.  Also, cover with layers of compost, wood chips, and manure.

Aw man, that sucks. A friend of ours has had this happen to her...multiple times. She's going to put up a taller fence, but it's still soul-destroying to see her fruit trees shrivel up after they've been hit.

Can you put up a camera or two? They're pretty cheap these days and you don't need super quality, just enough to ID and put a timestamp on it.

Dang William that really blows. Here are my thoughts and suggestions. I advise against buying roundup ready anything, that just puts money in bad peoples pockets and supports that industry. If you really think he did this, and may do it again, I suggest a trail cam, or two! Without proof anything is just hearsay and speculation but if you are able to get photographic evidence and proof that he is intentionally spraying your plants beyond his property line, then you are able to take real action and seek damages, which I believe any judge will award in your favor if pictures come across their bench. And pictures from a trail cam may show that there is no nefarious agenda or ill intent and it is just herbicide drift, which I think is terribly unfortunate.

WIliam, if you're looking for plants that are roundup-proof, you could do a border of NZ flax (Phormium tenax). It gets up to 3m tall (and you could easily hide cams in it). Not sure if it would be hardy in your region but possibly, as there are alpine varieties.

Camera may be a good idea. In many states, there’s a special triple damages award for intentional or reckless (some places negligent) destruction of trees. With video, it can be a small claims no lawyers matter that would deter future misbehavior.

James Freyr wrote:Dang William that really blows. Here are my thoughts and suggestions. I advise against buying roundup ready anything, that just puts money in bad peoples pockets and supports that industry. If you really think he did this, and may do it again, I suggest a trail cam, or two! Without proof anything is just hearsay and speculation but if you are able to get photographic evidence and proof that he is intentionally spraying your plants beyond his property line, then you are able to take real action and seek damages, which I believe any judge will award in your favor if pictures come across their bench. And pictures from a trail cam may show that there is no nefarious agenda or ill intent and it is just herbicide drift, which I think is terribly unfortunate.

Herbicide drift is illegal too.

Presuming you have a history with the neighbor and reasonable discussion has been attempted and failed. I follow these types of threads in other fora and usually progress as follows:

Vague description involving some action by a neighbor involving the property line
Suggestions as to how to deal with the action, usually reasonable things like cameras, fences, trenches, etc.
Descriptions of bad experiences others have had with bad neighbors
Suggestion of legal action against neighbor based on the thinnest pretext
Detailed description of fences others have put up
Discussion ensure as to whether the OP actually knows where the property line is, usually devolving into speculation on easements and adverse possession, almost always from the perspective of old law and a different state from the OP.
Suggestions of ways to get even, some sort of spiteful action.

Without additional detail and having dealt with chemical happy neighbors, or more usually their yard service, a solid stockade style fence on the property line and the guy will likely forget there are any plants. Some types of herbicides are very prone to unusual spreading once aerosolized where they will float quite a distance and it is entirely possible something floated over due to the specific conditions, wind being the most obvious factor (though spraying during wind is proscribed). Before going forward my question would be WHY is chemical neighbor spraying next to the property line? Is it the ever popular quest for clean edges to lawns, I.e. kill the dandelions, or is it something more ominous? You mentioned he will try to spray your property despite a fence, hence my take is you have a history with this person, which begs the question as to why would he spray your stuff if you have spoken with him (assuming a him) about the subject.

A stockade fence he can’t see through will be a nice deterrent. May like deer won’t jump over a fence they can’t see through, neighbor won’t spray over fence.

My question,  should I seek out roundup ready crops and weeds?  

That seems like feeding the beast.

A mediator helped me in the past.  

Keep a detailed record of your interaction with the neighbors.  Describe what you experience.  I saw the plants along the boundary next to so-and-so's yard died suddenly.  Record tangible tings that can be proved and whitnesses.

If you are concerned about the damage to your property, it might be time to consult the authorities and ask for advice on how to prevent it.

Thanks everyone, for your responses.
James,  you are on the money.
This neighbor asked that I not build a privacy fence on the property line.
He was concerned that it would block sunlight to his basement windows.
So I built a chainlink fence along that stretch to accommodate him.
Latter he complained to me and authorities about what I was doing on my land.
The authorities were only able to see my land from his property.
I was cited,  fined,  my property seized,  trees ripped from the ground and I am still dealing with the outcomes.
I was furious.
But I stayed my hand.
I was looking for positive reactions that could help.
I just don't have the resources to devote to vengeance.
Eventually I decided to plant willows, in a line along the fence.
A hedge,  quick growing and meant to obscure the view,  thus helping him and me.
After the willow stakes sprouted,  someone tried to break them off at the ground level.
Willow is tough, they survived, I straighten them up and they thrived.
Then they browned, withered, and died.
Hmm.
Then the well established crab apple tree,  along the same fence line browned, withered,and died.
Hmm.
Then the peach tree across the yard browned and withered.
Other plants near to these plants suffered,  but didn't die.
The peach tree might make it,  but this year's harvest is stunted and tainted.
I'm convinced.
I am building a privacy fence, and setting up cameras.
I will plant along this property line with something new.
Roundup resistant plants don't produce roundup,  they resist it, so I am fine with using them.
They emerge naturally via selection,  as well as via genetic engineering.

I would sell this property,  but no one wants it except for the hateful  neighbor, and I just don't want that.
I could let the government take it,  and I might.
I'm trying to avoid falling into the sunken cost trap,but right now I'm following the advice of my lawyer and building a privacy fence.

Goes to show how good neighbours are a blessing, bad ones are, well, you know.

I'd still use some camera surveillance to ensure the fence isn't damaged or to capture illegal entry to your property.

Evidence is everything.

Good luck.