Cedar is a fragrant evergreen tree, of which there are many varieties. The Juniperus virginiana, or the popular aromatic red cedar, has seeds housed in a fleshy material. Collect several seeds from your cedar in August, since germination is not always successful. You should be able to get some seedlings started within a few months of harvesting the seeds.
Place the seeds into a container and cover them with water. Macerate the seeds to remove the inner seed from the fleshy material. Place them in a glass container and cover them with the toilet bowl cleaner. The lye in the cleaner will break down the fleshy coating on the seeds. Let them sit covered for about two hours. Rinse the seeds, being careful not to get any of the caustic cleaner on your hands or skin.
Store the seeds in a dry, warm place wrapped in a paper envelope or paper towel for three months. This is the resting time for the seeds before they go through their cold storage.
Place the seeds in a plastic bag stuffed with a handful of damp sphagnum moss. You should not be able to squeeze the water out of it, but it should feel damp to the touch. Close the bag and place it in the back of the vegetable drawer of your refrigerator for another three months. You could plant the seeds directly outside, but there is a good chance they will be eaten by squirrels or bugs.
Plant the seeds in regular potting soil about 2 inches deep. Water them often and place in a warm and sunny spot--outside if the weather has warmed up to be well above freezing at night. Germinated seeds should sprout within two to three weeks.