Plant layering is a means of propagation using the stems or canes from plants without taking cuttings. The benefit is that the parent plants root system supplies the new plant with water and food until it can grow roots of its own. The soil must be kept moist until roots are established and it can take several weeks for the plants to root sufficiently that a new plant may be severed from the parent if you desire to transplant it somewhere else in your yard.
Ground layering occurs naturally with plants like ivy, strawberries and spider plants that produce runners (stolons) without any outside encouragement.
1) Simple layers— in the spring, bend a low growing stem close to the ground and cover part of it with soil. Stems can be anchored with U shaped pins if they are resistant to bending. Be sure that the stem stays covered and moist. This works well with climbing roses and honeysuckle.
2) Tip layering—insert the tip of a plant (new growth) into a shallow pit in the soil (or pot) and cover with dirt. This method works well with raspberries and blackberries. In fact, just try to stop blackberries from doing this on their own.
3) Compound or serpentine layers—this where the stem is bent to make contact with the ground as in example 1 above, but where it is woven in and out of the soil two or three times. The stem or cane will likely need to be pinned with U shaped anchors. This works well with wisteria, clematis and grape vines.