The Colorado Department of Agriculture has given the nod to using four hemp seeds for industrial crops after a lengthy testing process.

Industrial hemp seed varieties are required to pass statewide THC validation and observation trials before they can be grown by the Colorado Seed Growers Association for production. Colorado state law requires that industrial hemp tests at or below 0.3 percent THC concentration.

The department planted five varieties of hemp across Colorado’s diverse growing conditions to test whether the plants would grow to maturity, a requirement of Amendment 64, the law that legalizes marijuana in Colorado. Four of the varieties met that requirement. The Department of Agriculture reminds growers that the seeds are prohibited from crossing the state line, even though the plants would have no recreational benefits.

Bialobrzeskie, Beniko, Tygra and Bija seeds can now be grown the state to harvest for hemp fiber and grain.

The department says it grew test plots in the northeast, Arkansas Valley, Front Range, the San Luis Valley and on the Western Slope to provide a broad representation of Colorado’s growing conditions.