Every year a couple of weeks before the Persian New Year Iranian ladies set out to grow their Sabzeh for their "Sofreh", which is a special holiday table setting prepared for the new year. Either barley or lentils are placed in a shallow dish and sprayed over and over with a water mist until they start to sprout and grow.
Image Via Wheres the Revolution
Once the Sabzeh have reached a decent size, a ribbon is tied around to make it more festive looking. The sprouting seedlings, which are supposed to have absorbed all sickness and badness that might have been lingering around, are kept until Sideh-be-dar (13 days after Norouz)and are then thrown into running water. This act is meant to rid the occupants of every household from any lingering evil spirits. The Sabzeh has grown quiet a bit by this time before it gets tossed, people like to make knots and make wishes for the new year. It is said that if you are wishing for a spouse, you better knot the Sabzeh!
On a side note, as a child living in Iran I thought it was the funniest thing when families placed their super huge platter size Sabseh on the hood of their cars and drove off in search of green pastures with a stream. The sight was priceless! I looked high and low for a photo to share, but could not find one. Anyone reading this please send me a photo if you have one!