Q.Chocolate mimosa tree has never grown chocolate color.
Bought as a twig in pot, planted it. 1st year chocolate color, after that always green color like regular mimosa. Very healthy, very tall, never flowers, about 12 ft tall, would have been taller but lead branch was broken off in storm, tree is 8-9 yrs old, majority full sun with shade towards evenings.
Certified GKH Gardening Expert
Since it was just a twig, I'm wondering if it was seed grown. In that case, you wouldn't get the same properties as a Chocolate mimosa aesexually propagated.
It starts out green then turns burgundy and brown during the course of the summer. Do you have the tree planted in acidic soil? You might want to get a soil sample tested and look for pH level as well as any soil deficiencies. Especially since it isn't blooming either. Mimosa also likes moist soil, so make sure it is adequately watered.