The cannabis industry is generating plenty of new economic opportunities. Here are five areas that have grown up around legal marijuana.

1. Packaging

With legal ganja heavily regulated by state governments to avoid accidents like unintended consumption by kids, proper pot packaging and labeling are imperative. Kush Bottles, the manufacturer of child-resistant plastic cannabis containers, and Stink Sack, which makes odor-free opaque bags with childproof slide locks, are new two companies in the game.

2. Real estate

CBRE, the world’s largest commercial real-estate-services firm, reports that legal cannabis “kick-started the recovery of the industrial market in Denver,” resulting in record-high rents and record-low vacancies. From 2009 to 2014, a third of all industrial space leased in the Denver was for cultivation purposes. During that period, one out of every 11 industrial buildings in central Denver housed ganja gardens.

3. Industrial agriculture

Companies are producing cutting-edge agricultural technology, fueled by consumer...