Which variety of salvia blooms the most prolific with the BLUEST coloring and hardy to zone? Want something for companion to my pink knock-out roses. Thanks.
salvia patens "Genitian Salvia"
There you go.
spelling is G E N T I A N salvia
Salvia patens is a real true blue. Ignore names like 'Gentian Blue'..it is the same plant. A large, vigorous from of this species is known as S. patens 'Guanajuato'...this is spectacular, with royal blue flowers. Also S.patens 'Cambridge Blue' has the most wonderful bright, pale blue flowers.
Other true blue Salvias...S.sagittata, S. sinaloensis, and S. cacaliifolia. Also many of the S. guaranitica and S. mexicanas. What about S. urica?
Patens will not be hardy in your zone. Is it just me, both I find this species a big pain in the %# to keep happy. That being said, it sure is beautiful, and I wish it did better for me.