Lynn,
Yes J. 'Emerald Spring' is a hirta x sobolifera (now a subspecies of hirta) cross. It has the form of the hirta and the size of the sobolifera. Neither of these parents bloom very often but Polly Bishop had large clumps and there was good bloom on both in order to make the crosses. These roller species seem to bloom better in a hot year. Think that means everyone except Oregon! Actually today it's even sort of hot here.
Enjoy!
Kevin
