Prized for its nutrient content and new flavor, wheatgrass is the young, newly sprouted seedlings of the frequent wheat plant (Triticum aestivum). The sprouts are simple to grow at home, particularly in a greenhouse in which the growing conditions can be tracked and readily controlled. To ensure that the bananas are safe to eat and free from potentially dangerous pathogens, the seeds and the growing medium has to be restarted as well as the greenhouse thoroughly cleaned. But you must still clean the wheatgrass sprouts before consuming them to avoid food-borne infection.
Measure out sufficient seedling compost to fill out a 3-inch-deep nursery flat. Place the compost in a microwave-safe bowl. Heat it in the microwave for two minutes to kill any germs or other dangerous pathogens.
Permit the seedling compost to cool completely. Wash a 3-inch-deep nursery flat in warm, soapy water, rinse it thoroughly. Fill it up with the sanitized compost. Firm the compost well, then gently roughen the surface with your hands.
Put the wheatgrass seeds in a saucepan. Pour in 3-percent hydrogen peroxide before the seeds have been covered. Heat the saucepan on the stove until the peroxide reaches 140 F. Maintain a 140 F temperature for 10 minutes to sanitize the seeds.
Rinse the wheatgrass seeds under cool, running water for a single minute. Wash the seeds in a bowl of water to get a half-hour. Skim off and discard any one of those seeds which float to the surface, since they are most likely not viable.
Scatter the wheatgrass seeds across the roughened surface of the compost. Aim to space the seeds 1/2-inch apart. Press them onto the surface with your palm. Cover them with a 1/16-inch-thick layer of compost.
Place the nursery flat on a garden seat along the south- or west-facing wall of the greenhouse in which it will be given a minimum of six hours of sunlight every day. Water the wheatgrass seeds thoroughly after positioning the nursery tray in the greenhouse.
Warm the base of the nursery tray with a propagation mat set into 70 F. Cover the tray with a 3-inch-tall clear plastic propagation dome to help hold the heat and humidity around the seeds. Water the seeds with a spray bottle whenever the compost feels dry on top.
Watch for sprouting in seven to ten days. Remove the propagation dome once the wheatgrass seeds deliver up sprouts. Do not thin the seedlings as soon as they emerge. Maintain the propagation mat in place for just one week after sprouting, then remove it.
Preserve a daytime temperature of 75 F and a night temperature of 55 F. Open the ventilation system if daytime temperatures leading 85 F. Warm the greenhouse if night temperatures drop below 50 F.
Decrease watering marginally after the wheatgrass sprouts emerge. Permit the top inch of compost to somewhat dry out before adding more water. Tip the nursery flat on an angle after watering to pour off any accumulated water.
Hang a sheet of 20-percent shade cloth several feet over the nursery tray if the greenhouse receives direct sun at midday during the summer months. Remove the shade cloth during prolonged periods of foggy or cloudy weather.
Harvest the wheatgrass when it reaches two to three inches in height. Snip off the sprouts close to the base with sanitized scissors. Wash the sprouts thoroughly before eating them.