Sativa Labs recommends clients follow USDA’s sampling guidance (National Agricultural Library, Agricultural Research Service, U.S. Department of Agriculture) promulgated by the USDA. Generally, the top 3″ to 5″ of the plant should be harvested. If you intend to dry your sample prior to shipping to us, please be sure to go “low and slow.” Recommended not-to-exceed temperature is 150 degrees for at least 24 hours.