I love the accent this gives to my garden. Before it blooms it stays shorter giving my bed nice green color but allowing the other plants to show. When it blooms it is striking and everyone feels the need to touch them.
I will have to say soil conditions & lighting greatly effects the size of these plants. I planted 6 at the same time, but some were only 2 feet tall and one in bloom was 4 1/2 feet tall which i had to move to the back of my bed. It ended up being perfect as it nestled between 2 shasta daisies creating a striking purple/white back border which everyone commented on.
The smaller ones were cut and mixed with my lillies, coneflowers, and roses into lovely center pieces as they make a great filler.