General Washington has a trait which is initially not pleasing - the old 
blooms age rather quickly and the dark dried petals persist on the 
bush.  But it also has rebloomed well for me two summers in a row now.  
Because of my annoyance at the appearance of the old blooms, I refused 
to deadhead it this year.  Despite this, it remained the best of my hybrid perpetuals 
for rebloom in mid-summer.
So no surprise that I am growing very fond of this plant.  It has been 
slow to build size but was big and sprawly enough this summer to allow 
some fairly heavy cutting back.  Will this experiment lead to bloom in 
fall?  I await the answer.