Also the specimen from which this plant originated must have been planted pre 1980 judging by its proportions when I saw it back in 2000. How time flies…
Have you considered Snowfall, which came out of Jeanne La Joie (as spelled on helpmefind). I have both in my front garden. For me Snowfall never has been as vigorous as its mother. It was introduced in 1988, not particularly winter hardy here when it hits 0 F or below. So it never gets really going for size. It does bloom reliably most all through the summer. Unfortunately HMF has only one photo, but that one is strikingly like your for the flower. Foliage looks like mine, so do the fat buds.
Hi Larry. It is definitely not ‘Snowfall’. Snowfall, as I see it pictured on HMF, shows a far flatter open bloom with petals rolling to form almost a point on their edges. Mine opens with wavy petals. Also the color is different, mine is not 100% white, it has a very very faint blush overlay to the white base as it where, and the central stamen/pistil area is browny coloured.
George, I like your idea of combining a climbing miniature with the Hulthemias. I have a fairly clean climbing mini that is also a good seed parent to try.
Jadae - can’t check on your idea yet, HMF website is crashing on me…
Peter Harris - ‘Sea Foam’ is certainly available here. My local rose grower offers it as a weeping standard. You definitely might be onto something here I think. I will check the details of ‘Sea Foam’ out on HMF when their site is up again!