Perennials are plants that grow year after year without reseeding. Perennials are propagated in many ways, including divisions, cuttings, and from seed. Producing perennials from seeds allows you to grow varieties that are not often grown in greenhouses, ready for transplant. One disadvantage is that some perennial plants do not produce seed that propagates a new plant, says the Virginia Cooperative Extension. Check the plant variety you are trying to propagate to ensure it produces a true seed before sowing its seed.
Place seeds that require a cold treatment before germination in a plastic bag and place the bag in the refrigerator for four weeks, says the University of Illinois Extension.
Fill your seed tray with sterilized potting soil available from a local garden center. Water the potting soil until water runs out of the bottom of the tray and drain the excess water.
Sow the seed at the depth indicated on the seed packaging, says the Ohio State University Extension, so the seed gets the right light and heat requirements.
Cover the pots with a plastic bag to retain moisture and place the pot in a warm spot that is out of direct sunlight but is between 65 and 75 degrees Fahrenheit. Remove the plastic bag once the seed sprouts from the soil.
Transplant perennial plants into the garden once the plant is 2 to 3 inches in height. Place the plant outside for greater lengths each day to harden it to the weather. Transplant the plant into the garden at the same depth it was planted in the seed tray.