I have planted 4 'joi choi' pak choi Brassica Rapa Chinensis plants. I live in the Salt Lake City Utah area and planted my starts the first week in April. I guess I was expecting it to grow taller and fuller and look like the bok choy I by in the store. It looks similar but it is only about 7 inches tall with beautiful green leavesa and a pretty yellow flower. Should I have harvested it before it flowered? or Will it continue to grow? Is it an annual or perrinial?