He is experienced in the most profitable industry in our area (cannabis) and works steadily with that, and I do believe he could make the payments with little to no trouble, but his lack of financial "adulting" has me worried.  

After chatting with him for a while, he fessed up and said that he was a cannabis grower and recently just opened a dispensary a few blocks down the street from my rental property.

For example, if you have a GameStop anchor in the property then complementary businesses could airsoft store, kids hair salon, skateboard shop, cannabis store (you'd be surprised), etc. 

Hey Jack, The rules vary from state to state but if your tenant is on the authorised medical provider managed database he is allowed to grow up to 6 plants in his domicile and to have up to 8oz oz cannabis for his own medical use in his possession from his own plants in your state..Here's a link to the breakdown:https://www.leafly.com/news/cannabis-101/home-cannabis-cultivation-laws-a-state-by-state-guide#washington

They did not want to be on title I invest in properties that I lease out to cannabis growers and they were concerned that somehow it would be bad if they were on title  

@Lucy CanWith the amount you are putting in, I'd approach a HML, you will pay a higher interest rate, but anything with a cannabis related tenant is nearly impossible to get a loan for. 

Need recommendation for an insurer that will cover a cannabis dispensary.

...he/she hasn't listed any grow houses for sale:http://www.nydailynews.com/news/world/british-real-estate-website-mistakenly-lists-apparent-cannabis-farm-article-1.1508578

Otherwise a commercial loan would be the next-best thing, but it is still going to operate off the appraised value.Then there's cannabis dispensaries. . . they'll overpay for anything!

There is a plethora of Cannabis-zoned land in CA, and farming (non-cannabis-related) is already quite prevalent out there.