I have one and it is a beautiful tree. The foliage and flowers are beautiful. I got mine from a mail order catalog so it was tiny. It is 9 years old and only 5' tall. It has grown slow for me. I have it in a crowed flower bed in front of an arborvitae hedge. It was always getting shaded out by the perennials and the cedar hedge made for dry growing conditions. I was planning on cutting it back every year, but it was always so small I never did. It's finally taller than the surrounding perennials and finally starting to grow. It flowered for the first time this year. The flowers look like impatiens. I am afraid to cut it back now as it took 9 years for it to get this big for me. Here is a close up of the flowers. Karen

If you pollard it you won't get flowers. However, it's not a dwarf: one in Poland was 42' tall by 1973; another, in Port Coquitlam was 51' across in 1994.