Would yellow bearded irises or 'Happy Returns' daylilies work to screen the bottom of the propane tank? Even when they aren't in bloom, I like the foliage of irises & DLs. I saw another DL (at costco, bare root) called 'Scented Returns' that seemed to be daffodil yellow, like 'Happy Returns'.

It is too shady there for iris or daylilies to bloom. I think it is probably a bit too shady for the honeysuckle to bloom too, but at least the foliage is a nice backdrop. I have Happy Returns as a pass along from Sallyg, but the deer keep eating it. I love the soft yellow color of that one. I need to come up with a way to keep it safe from the deer browsing. Not a big fan of wire cages though

I have Corydalis seedlings that pop up every year in places where they can't stay... a few of those, and you'd have a reseeding population. I'm not sure if they're biennial or short-lived perennials, but there always seem to be enough of them growing tall & blooming.

Corydalus would be nice. I may have one survivor that was left here after last spring swap still in a pot, but I would welcome more