Brenden and Missy I do not think the black and blue salvia is cold hardy in Michigan maybe in a warmer winter only. Here it is invasive and self sows. I think you would need an expert from Michigan. Even if you saved seeds I do not think your length of growing season would work for it.
The May Night can be in bloom all summer if you continue to cut the flower stalks off. The flower is purple and it's stalk green. You cut green off, when there is not any purple left. If your plant is established and you cut down too far no worries it always grows back bigger. I do not know how you get them ready for winter. Whether you cut back in fall or let it die naturally to insulate and keep water out of its stems. Really probably need someone here who has cold weather experience. It is a beautiful blooming carefree plant that is a bee magnet, that is not invasive.
May we be blessed with some gardening help from Michigan! May you both have many joys come your way this week!
