Flax (Linum usitatissimum) is grown today for its valuable seed oil used in health food supplements and artistic mediums. In addition, flax is the basis of fine linen and paper products. For growing flax, choose a location with well-drained soil, free from salt deposits. The agricultural department at North Dakota State University (NDSU) recommends using flax seed in a crop rotation program, planted no more than once in a three-year period. Flax seeds grow well in soil that produces satisfactory barley and wheat crops, but avoid planting flax where you grew potatoes, sugar beets or canola in the previous year.
Work the soil before sowing flax seeds. If you're planting a small pot of flax seeds for personal culinary use, sprinkle them liberally on the surface of sterile potting soil and gently mix them into the top 1 inch of soil. Work large acreage to a depth of 8 inches at least twice in the month prior to sowing flax seeds. Allow the soil to rest for at least one week prior to sowing. Germination rates increase when the surface soil is slightly compacted but not crusted. A drill/packer may be beneficial if the soil is very soft. Set all seeding drills to a depth of between 1 and 1 ½ inches. Thirty plants per square foot is the minimum for a sufficient harvest, while 70 plants per square foot is a bumper crop. As a cool season crop, plant flax seeds in the early spring in northern regions (Zones 7 to 3) or in early winter in southern regions (Zones 8 and 9).
In a small culinary pot, pull weeds by hand. For agricultural flax seed production, successful weed control takes place prior to sowing the seeds. Flax crops suffer if the plants must compete with weeds, so proper crop rotation is essential. In addition, tilling weeds is a better way to control them, as opposed to applying a topical herbicide or preemergent.
When at least 90 percent of the bolls, located on the tip of the flax stalk, turn brown, it's time to harvest. Because flax is a semidelicate stalk, use a drum-type gleaner to reduce the amount of flax stalk that is destroyed by being bent to the ground. After the gleaner makes the initial pass to harvest the flax seeds, swath the spent flax stalks into rows to sell as flax straw. Do not bail the flax stalks until any residual moisture evaporates.