Hi, was hoping for some opinions on how you would plant these. Would you put firebush in front of, in back of or mixed with B&B salvia? I would like to eventually have a lot of B&B since the hummingbirds love it so much. I believe they will both die back in the winter and come back in the spring. I am new to frost and freezing so any advice is appreciated!
The Firebush can reach 10-12' at maturity unless you are anticipating one of the newer, dwarf varieties. If you are looking at one of the newer hybrids, be certain it is valid in your area...several of the newer ones are listed at zone 7a-8 only. I Yes, they are all deciduous, but will return from the roots...I do not cut my firebush down until the new spring growth is well over 12" tall...
As for the B&B (presume Black and Blue), you need to consider how much space you wish to commit to that singular salvia. It will spread across a 12X12' area in 3 seasons or so, but only gets approximately 20" tall at maturity. Blooming is erratic in my area, but it is evergreen or rather everlime. There are many more salvias that are beloved by the hummers and butterflys that are easier to maintain and enjoy.
I had a beautiful fire bush (Hamelia patens) in Louisiana (New Orleans area) that came back year after year. It did reach about 7-8 feet tall, but died to the ground every year. Sometimes it took it while to come back out, but it did always come back. I tried the dwarf variety several times, but couldn't get it to overwinter. The Black and Blue salvia I have here in my yard now gets between 4 and 5 feet. Both are fantastic hummingbird plants.