So sorry Sergey didn't grow for you. Clearly there is more to it than climate zone - you and Brad are both in 5b. I had in one location and it didn't bloom. Moved both it and Captain Thunderbolt to a new area I cleared where the soil is sandier . The ground is sloped so it is extremely well drained (and maybe a little sunnier) and both took off. In the first location, they were next to Wintry Sky, which was thriving there.
Adding this comment later - the soil in the first location was what I considered my best soil - it had been an organic veg garden for years so it was rich and loamy. But of course for veg, drainage and rot are not an issue - they're often not even in the ground here when iris season starts and they're compost by winter, and soil that holds water is the name of the game for veg.
tveguy3 said: Sergey Look is nice, maybe it would grow here, as Sergey has failed 3 times for me, it always dies over the first winter. 
I've quit trying, guess it doesn't like my climate.
20-97 Moment to Savour X 13-97 (Ride The Waves X My Beloved) A is sure a lovely lavender with such nice ruffles and form.
