I am not worried about them marring my velvet smooth lawn (grin) but I did have horsetail that invaded my garden and I swear the only thing to be done was take off and nuke the place from orbit. Worse then just the weeding was that it would kill off the other plants.
If necessary I can stick it way in the back where it will bother no one but back there it will become deer food. Nearer the house Evangeline and Priscilla the Attack Cows with the help of Lilly the Dog keep the deer away.
I’ll ask, definitely!
I heard back from two salsify growers so far. They both say that the key is watching the seed-head when it forms. The seeds are carried by wind the same way dandelion seeds are, but salsify seeds are bigger so they should be easier to contain. If you decide to let any go to seed, put a bag or something over the flower after the petals fall away. As long as you do that, they say you won’t have a problem.