I'm smitten with Euphorbia 'Blackbird' for its dark purple/maroon foliage. I'm wondering, however, if it's an aggressive re-seeder like some of the other euphorbia hybrids.
I learned my lesson from a Euphorbia 'Dolce Vita' to be careful about which perennial euphorbia I should plant. When 'Dolce Vita' went to seed, it would shoot the seed out, sometimes 20' from it! I had it 7 years ago & 3 houses ago and I still find volunteers in potted plants!
This post was edited by manifest on Sun, Apr 28, 13 at 23:13