Pieces of stem that contain at least two joints can be inserted as cuttings in pots of sandy soil or in a mixture of sand and peat moss. The pots should be kept at 70-75 degrees F., and shaded from direct sun until they are well rooted. Trailing varieties will often root at any point where the stem comes in contact with the soil. Pin the stem securely onto the soil in a separate pot with a hairpin or bent wire. It will be rooted in 4-8 weeks, and you may then sever the new plant from the parent.
Offsets are new plants which emerge from the base of the plant or from the roots themselves.
Once an offset has a sufficient root system to support itself, it can be removed from the parent, by cutting it off with a sharp clean knife. Philodendrons may also be grown from seed, but this is a long, slow process to get a specimen sized plant.