Wheatgrass, or Triticum aestivum, is an edible crop sometimes grown at home for use as a dietary supplement in fresh juices or salads. The plant is sprouted in shallow containers and the young, succulent leaves are harvested and consumed before the plant fully matures. To harvest seed from wheatgrass plants, they must be allowed to mature and set seed, which takes approximately three months from sowing to harvest. Harvesting wheatgrass seeds is very simple -- and the seeds can be stored for up to one year in an air-tight container for future planting.
Allow the wheatgrass to mature fully and set seed in late summer. Wait until the wheatgrass becomes yellow in color and completely dried out before harvesting the seed.
Gather the ripe seed heads into 2-inch diameter bundles. Tie the bundles with heavy-duty string 3 inches below the seed heads.
Sever the bundles 3 inches below the string using a pair of pruning shears. Set the wheat sheaves upright on the ground. Leave them for five days to dry out.
Gather the seeds from the sheaves once they have thoroughly dried. Work with one sheaf at a time. Hold the sheaf just below the string with the seed head upside-down inside a 5-gallon bucket. Beat the seed head against the inside of the bucket to knock the seeds loose. Repeat until all the sheaves have dropped their seeds.
Winnow the seeds outside on a warm, breezy day. Pour the wheat seeds into a wire-mesh colander. Rub the seeds lightly against the mesh to loosen the papery outer hull surrounding each wheat seed. Toss the seeds in the colander while allowing the wind to blow the papery husks away.
Pour the winnowed wheatgrass seed into a sealable plastic container for storage. Seal the top and place the container in a cool, dry place such as a refrigerator or cupboard. Store the wheatgrass seeds for up to one year before sowing them.