Leave them alone. These are some of the most cold hardy shrubs available. Frost damage to foliage should be slight, if any, and the plant can withstand a complete defoliation should catastrophic temperatures befall :-)

Thank you!

let me put it this way.. if you figure out how to kill them.. let us know .. lol ...

hardy or not.. that does not mean tender leaves wont be damaged.. it simply means you can beat this thing with a stick.. and it aint gunna care ...

ken