Propagating perennials from basal cuttings

How to take basal cuttings from a perennial and trim the base before covering it with a bag in a pot until it’s established when the cuttings can be separated and re plantied or plated out
How to take basal cuttings from a perennial and trim the base before covering it with a bag in a pot until it’s established when the cuttings can be separated and re plantied or plated out