NBA star-turned-marijuana mogul Al Harrington says his Viola company's sales are through the roof since the coronavirus scare took over the U.S. ... and now he's scrambling to meet the demand.

Of course, Harrington has turned into a highly successful weed advocate and entrepreneur in his post-playing days ... sharing the medical benefits for athletes, as well as, the average folk.

We spoke with Harrington about the insane demand for cannabis products right now -- after all, EVERYBODY is stressing out over COVID-19 -- and he says his sales have DOUBLED.