It's on a state to state basis. Here in Washington, the intent of the grower designation provision was to help patients who either are too sick to grow or aren't gardeners. Pretty sure nobody would hassle you here, but can't say about other states.
Check the statues where you live. They will say whether a careprovider is required to have a recommendation. If they don't specifically say one is required (and your state is as tolerant as mine), I'd go for it, BUT stay very legal with paperwork and plant count.