Hi Jessica,
Medicinal and recreational cannabis use is legal in the state of California and is not federally legal in the United States. If you're not comfortable with cannabis consumption on your property then be transparent with your listing.
If you permit alcohol consumption, will you also permit cannabis edibles, tinctures and topicals? Are you flatly against everything cannabis or is it the smoking that bothers you?
This matters for the language you'll use in your listing regarding cannabis consumption. Rather than using the word "smoking", you may prefer the word "consumption" followed by a list of what your definition of consumption is.
Be transparent with your guests on why you're not cannabis friendly inside your home or on your property. State this near the top of your listing so potential guests will see this rule immediately. Cannabis consumers do not wish to book a non-cannabis friendly home.
Here's a sample of how to politely phrase it while clearly stating your boundaries:
"We're not a cannabis friendly accommodation. Although cannabis is medicinally and recreationally legal in the state of California, it's not federally legal in the United States. Our employers abide by federal cannabis regulations which means we do to. Kindly do not smoke cannabis inside our home or on our property - this includes smoking dry flower, dabbing or vaping oil cartridges."
or,
"We're not a cannabis friendly accommodation. Although cannabis is medicinally and recreationally legal in the state of California, it's not federally legal in the United States. Our employers abide by federal cannabis regulations which means we do to. Kindly do not consume cannabis inside our home or on our property - this includes smoking dry flower, dabbing, vaping oil cartridges, edibles, tinctures and topicals."
Education is key and this is your home. There's still stigma, federal laws and random employment drug testing associated with cannabis consumption and if you feel worried about your job or what neighbours will think or do if they smell cannabis, then your choice to not allow cannabis consumption on your property is legitimate.
Be kind, open minded and remember not all cannabis consumers are disrespectful or hippies or generally undesirable.
Best wishes,
Unity