Question: How do I make a tip layer? What plants grow best this way?

Answer: If a portion of a plant either trails along the ground, or can be pulled down into contact with the ground, it may form roots where it makes that contact. Strawberries and airplane plants do it naturally, but many other plants can be encouraged to form tip layers simply by pulling their branches to the soil. Wound the bottom of the branch lightly with a sharp knife, as you would for a stem cutting, dust it with rooting hormone powder, then secure it with a small piece of a coat hanger or similar wire bent into a wicket shape. You can also cover the area with topsoil, both to give the new roots soil in which to form and also to weight the stem down. Once the new roots have formed, you can cut the stem and replant the newly rooted plant.