They would still answer to the feds. The Supreme Court has ruled they may use peyote, sage and other plants in their spiritual practices, but did not say the word Marijuana. The feds donā??t agree (surprise) they see it another way but they always do.
You can buy cigarettes on the reservation without paying federal or state taxes but an open garden is still out of the question.
It was tried in Arizona a few years ago but the feds moved in killed everything and then ran off like thugs in the night.