I started a pot business! Can I protect my brand?
CONGRATULATIONS! And yes, you can—to some degree. Although protecting a pot brand is tough sledding, it's worthwhile. For purposes of this discussion, I will assume you have developed a logo, strain, slogan, or some other piece of intellectual property that is distinctive and unique, and that you already are using it out there in the world.
Most non-pot businesses protect their identities and products through federal trademark registrations with the US Patent and Trademark Office (USPTO). Unfortunately, USPTO will not issue trademarks for pot-based products. This is because trademark registration requires "lawful use in commerce" (cannabis is still a federal controlled substance) and because the Lanham Act bans registration for any "immoral, deceptive, or scandalous matter." Although you may argue that your pot branding is neither immoral nor scandalous, USPTO disagrees.
At the federal level, you can currently register weed trademarks only for ancillary products that do not contain weed, and do not facilitate the use of weed: Things like T-shirts and hats with your company logo should work, as well as certain informational products, such as websites. But you cannot meaningfully protect your dispensary name as it relates to selling weed, or trademark your prized strain. Unfortunately, I don't see this changing in the next few years at the federal level.
Because federal registration is not available in most cases, most pot clients I work with register their trademarks at the state level. Doing so is cheap and affords some protection here in Oregon, but probably nowhere else. If you want to obtain protection in both Oregon and California, for example, you would need to register the trademark in both states, which means you need to be using the trademark in both states. Again, tough sledding.
One nice thing about the dearth of federal trademark protection, along with federal illegality of cannabis generally, is that many prospective participants are still afraid to enter this industry. Big companies, like tobacco companies, will not go into marijuana until significant changes and assurances are in place. While those sidelined competitors wait for the tedious process of federalism to play out, you can develop your elegant brand with less competition.
I wish I could tell you that your cannabis branding is as easily guarded as similar assets in other industries, but it isn't that easy. Nothing ever is with marijuana. For now, the best strategy is to register your trademarks locally, enforce them vigorously, and continue to build goodwill in anticipation of federal legalization. At that point, you will have a nice head start on the big boys. They may even try to purchase you.