Salvias

Can anyone out there help! We have some salvias called 'Graham'does anyone know if they are hardy or not?

 

S. microphylla (syn), S. grahaminii is listed as a perenial and gets ** in My RHS A-Z which translates as frost hardy down to -5C average min. temp. Might need fleecing or a bit of straw if it's a hard winter.

Link to pic. Hope this is the plant you mean.

 

Thanks for your help frogesque, thats a great help.