Flax (Linum usitatissimum L.) is a winter crop in the southeastern United States that has potential in double cropping systems. This research was conducted to provide estimates of N, P, K, Ca, Mg, and Zn removal in the harvested portions of the crop (straw and grain). Four fiber‐type cultivars and one seed‐type cultivar were grown with and without irrigation for 2 years. The four fiber‐types were grown without irrigation in the third year. Nutrient concentrations were determined on the straw and grain in the first 2 years when the crop was harvested at seed maturity. In the third year, only nutrient concentrations in the straw were measured. Irrigation had a very limited impact on straw and grain nutrient concentrations. Differences among years were greatest for K concentration in the straw as K concentration in 2011 to 2012 was >1.00% and almost five times greater than in the other two years. Higher K concentration in that year is likely due to differences in the amount of K leached from the straw before it was harvested. Differences occurred between the fiber‐type cultivars and the seed‐type cultivars for both straw and seed nutrient concentration, but these were generally small. Nutrient removal in the flax straw and grain were primarily dependent on biomass. Our results indicate a flax straw crop of 5000 lb per acre will remove 48 lb N, 8 lb P, 13 to 56 lb K, 17 lb Ca, 9 lb Mg, and 0.28 lb Zn per acre.