Would Round-up weed killer kill iris, painted ladies and amyrillis?

Roundup works by being absorbed by the leaves, so if you want to use it among your other plants you will have to be vary careful not to let any of the spray get onto them. If the amyrillis and iris leaves have disappeared for the winter they will not be affected. Choose a day with no wind and shield the wanted plants from the spray and you might get away with it, but the slightest breeze will cause some of the spray to drift.

I think so. The poison is absorbed by the leaves and sucked down into the roots. I don't know about painted ladies, but you're thinking that iris and amaryllis grow from rhizome and bulb so should be ok, right? But I wouldn't want to risk it. What does the label say?

Yes. It's an herbicide that is designed to kill any plant. Pull weeds next to the plants you want to keep.

i know from experience, it will definitely kill iris. not sure about the others. i would suggest avoiding putting round up on anything you want to thrive. i'm sure it would not be favorable for them.

YES! Round up will kill everything.

Yes pull them out by hand and also lay down some mulch to keep them from coming back.

yes

use vinegar