Russian Sage

I bought a small Russian Sage plant many years ago after reading that it was named plant of the year (I can't remember which year).  We planted it in our perennial border next to our lavender, but it soon grew too large for the area and started to choke the lavender.  It is now in our herb garden, although the owner of our local nursery told us it was not edible (according to online sources the flowers and leaves are edible but do not have the same flavor as regular sage, I have never tried it).  It requires no special attention and is very tolerable of dry soil.  The leaves are feathery and the delicate flowers are light lavender.