Grass is a perennial plant that grows quickly and just about anywhere, depending on the type of grass you are growing. Some will do better in shady areas and others are better for the heat of the south. Of course, grass grown in better soil, with fertilizer and plenty of water will do better than neglected grass. In fact, you can encourage your grass to grow as a plant without cutting it and allow it to go to seed. This seed can be collected and used as any grass seed.
Work the soil well in the plot where you wish to grow the grass. You will need to eradicate any weeds so that they are not going to seed at the same time your grass is growing, which will contaminate the seeds. You can cover the area with a sheet of black poly for a couple of weeks to kill off any weeds sprouting by the process of solarization.
Form rows in the soil that are about 10 inches apart and running from north to south so that the plants get the most amount of sun during the day. Sprinkle your grass seed in the rows in a thin stream of about 10 seeds per 6 inches. Cover the seeds with about a quarter inch of soil and walk down the row to press the soil onto the seeds.
Water the planted seeds lightly every day until they sprout and then reduce watering to once a week. Since you are trying to get it to grow as well as possible, you will be watering more than if you were just watering your lawn.
Apply a liquid fertilizer every week to encourage a high growth rate. A mixed fertilizer with the ratio of 3:1:2 will provide a good amount of nitrogen for the plant growth but also with enough potassium and phosphorus for root and seed development. If you have a granular type of fertilizer it can be mixed with water at the rate of about 8 oz. per 5 gallons of water.
Keep the rows clear of weeds and allow the grass to grow until you see the developed seed heads showing. Typically this will take about a month to six weeks depending on the type of grass planted.
Gather bunches of the grass seed stalks together and cut them about 6 inches long. Place them in a paper bag upside down so that they seed heads are facing down. Use several bags if you are harvesting a lot of seed. Allow the seed to dry for a week or two in a warm but dry room.
Shake the bundles of grass seed in the bag so that the seeds fall to the bottom. If some still resist and stay on the stalk, you can run your gloved hand backward up the stalk to get all the seeds off. Throw the empty stalks into the compost and save the seeds for planting.