I do not seem to have trouble with the growth. I am trying to find the spot that I get the color that I like I think the last move is the best. Too much sun seems to bleach the yellow. I want the yellow.
All my gardens are improved with my homemade compost and leaf mold so it is rich soil. I say you can grow a dollar plant in hundred dollar garden soil. But you cannot grow a hundred dollar plant in dollar soil.