Wheatgrass, which is sometimes also sold as cat grass, is nutritious and easy to grow. Harvesting it is simple. If you find that you have harvested too much, you can keep any excess in your refrigerator until you are ready to use it. It will keep for a couple of days with no noticeable diminishing of flavor.
Do not harvest your plants until they have turned green. When they are too young to harvest, they will be yellow.
Measure your plants. They grow quickly, and can usually be harvested about a week after you have planted them. Harvest when they are 7 to 8 inches high.
Cut enough wheatgrass for your intended use with kitchen shears. Cut the stalks from about 1 centimeter above the soil.
Store any wheatgrass that you have harvested but do not need immediately in your refrigerator. Wrap a wet paper towel around the base of the bunch, then put it in a zip-top storage bag and squeeze all the air out.
Harvest wheatgrass fresh any time that you want to use it. Wheatgrass can be allowed to grow back for additional harvesting, but many advocates choose to grow a new crop every few days for maximum nutritional value.