Wheatgrass has become trendy as a juice product in smoothie shops, and is seen more often as a supplement than in its natural plant form. Although many smoothie shops open display trays of the grass for cutting and use, few people think about where or how that grass is grown. The process of growing wheatgrass is fairly simple, but depends on large amounts of water.
Soak wheatgrass seeds in a dish of room-temperature water for at least 12 hours. This softens the outer husk of the seeds and starts their germination; without soaking, the seeds will fail to sprout. Throw away any seeds that float to the top, then strain them and spread them on a dry surface.
Put a mixture of peat moss and topsoil into each growing tray, and build a foundation of at least 2 inches. Because wheatgrass is harvested when it's still relatively short, it requires only a shallow planting. Use disposable growing trays, which are easy to move and inexpensive to replace.
Sprinkle the wet wheatgrass seeds on top of the soil and cover them with 1/4 inch of topsoil. Put the trays in a warm, sunny location and water the seeds with 1/4 inch of water every other day to maintain the moisture they need. Look for sprouting in 10 days.