I have great love for G. Samobor too! I think it would depend on the density of the groundcover but I could see Samobor coming up through as well as seeding into groundcovers. I will have to check out Raven. G. p. Shadowlight is lovely too. Similar to Samobor but with a creamy yellow centre with the maroon markings around it. Same sultry flowers.

My experience is that samobor does not come true from seed nor is the original very persistent. Next generation foliage lost its clear varigation and the flowers became muddy mauve.

if you love it a lot buy more than one and be prepared to rouge out the seedlings that dont look look good.

it never lived long enough to be a problem and the pretty and the ugly died out quickly.

when you love a plant nothing should keep you from trying it in your own garden,

i would be interested in your experience and would like to know what happens in the future.

I haven't grown Raven but loved Samobor when I grew it in a previous garden. Mine was in a brightly lit but shady location. It self-seeded gracefully and the seedlings all remained true to form. Like many hardy geraniums, a hard prune after initial flowering will refresh the heavily pattered foliage and encourage a rebloom.

If I had a good spot for it in my current garden, I wouldn't hesitate to grow it again.

Mine are long lived and come true from seed also.

I'll be the one to throw cold water on the thread -- I really disliked Samobor. The flowers were ugly and the foliage was sparse, never got full and lush like other geraniums. I shovel pruned it after about a year.