NewLake—which has offices in New Canaan, Conn., and Chicago—is buying the Grassroots properties for $15.5 million and will reimburse Grassroots for $4.2 million buildout.

NewLake, launched last year, specializes in sale-leasebacks, buying shops or cultivation facilities from marijuana companies and leasing them back. It frees up capital, which is in short supply for cannabis companies because of a steep decline in pot stocks.

Financing is a particular challenge for marijuana companies because cannabis remains illegal at the federal level, which means traditional lenders won’t provide funding. And when it comes to real estate, properties with a mortgage typically can't do leases with weed businesses.

Some cannabis companies have gone public in Canada, but some of those stocks are down by half or more, making financing both hard to find and expensive—just as companies such as Grassroots need capital to expand in states such as Illinois, which recently legalized consumer pot sales, most marijuana companies are doing sale-leasebacks.

Grassroots and others, such as PharmaCann and Cresco Labs, are scrambling to line up retail locations in downtown Chicago. Opening a retail marijuana shop can easily top $1 million.

Coniglio says NewLake — whose backers include tech entrepreneur Al Goldstein and Pete Kadens, co-founder of cannabis company Green Thumb Industries — is raising more money. NewLake competes with Innovative Industrial Properties, a publicly traded real estate investment trust based in Park City, Utah, which has done deals with Chicago-based GTI and Cresco.