You say they are 'coming up along a fence'... Does that mean the neighbours have them too? We had/have that problem here. We dug out the ones on our side, but years later they still come from the neighbour's side. Chemical use is banned here so we just physically dig them out. Until the neighbour (now in his 90s...) removes his or a new owner there eventually does, we are resigned to the on-going need to watch for them and remove any we see.

put undiluted roundup in this very expensive applicator ... and just drip it down a couple leaves ..

no drift ... no excess application ... cant lose the bottle unless you go blind ... RU stores in the container for years ... but do store away from the hotdogs ... if it tips over.. it barely leaks out ... it can be closed ....

ken

brand isnt as important as container type

https://duckduckgo.com/?q=plochman+yellow+mustard&t=ffsb&iar=images&iax=images&ia=images

ps: if you dont want to kill the neighbors.. you will probably have to do some digging along the fence.. to make sure they arent connected ....

There are some in her yard and it looks like the daylillies from our property have spread over to her side of the fence. It’s chain link.

Why not wait until they bloom and you know for sure what they are ? I don't understand why people get in such a hurry to destroy things, especially when they don't know what they have. Are you planning to plant or build something there right away ?

Personally, I think a hundred foot row of them in bloom would be a beautiful sight.

I want to reclaim the space in favor of native plants.

I appreciate your point of view @woodrose. My mother is still sore about all of the rose bushes my brother removed from his new house and that was nearly 10 years ago. It's his home and they weren't to his liking. What can I say? I'll leave a few of the daylilies and if they're H. fulva, I'm getting rid of them. I have seen large patches of them blooming as they're quite common, but even the double version doesn't do it for me. I'd rather have native plants there, but that's just my opinion. If they turn out to be a really nice rebloomer or a color I fall in love with, I'll move them to a more suitable spot. I have areas that need more immediate attintion this year, anyway. I will, however, be getting rid of the deformed and diseased forsythia, if no one has any objections, LOL.

Well, I'm planning on removing my non-diseased and non-deformed forsythia so you'll get no objections from me. As some wise Ken on the board once said, "If it doesn't curl your toes, why stress over removing it." or something like that.

I have yet to find a way to kill them. I know others on this forum have had the same problem. I've lived in my current home around 25 years now and they still pop up amidst my hybrids occasionally. I have dug and dug and dug. Round-up only stunts the growth for one year, then back to full form. Any other weed killers are just laughed at by the daylilies! You need to plow up the whole area, then sift thru every ounce of dirt. One root left and they are back. If not the next year, within a couple of years.

That is a bummer. So far they are coming up along ~250 feet of the fenceline

I have been asking this same question. I asked the master gardeners at U of I if solarization would work. They replied maybe after about 2 years 🤦🏻‍♀️. It's back breaking work to dig up so many.

I just had 2 pop up this year after 25 years ago originally digging them all out. They last popped up about 2 years ago, Seems like almost every 2-4 years they appear. I would not count on solarization either. There are some in the woods a the back of my property where they get NO sun and still they grow though they don't bloom.

Plow and sift every bit of soil, not only where they are but out further than where they are. Their runners go pretty far sometimes. The ones that just popped up for me are about 6 ft from where they were.

I have them. And they are relentless. And they spread everywhere. I do a combination dig and roundup application. I am careful to trash the ones I pull out. I don't think you can ever irradiate them, but you can control them. Also if they are at your fence line now, I'm willing to bet there is at least elsewhere in your yard.