How does layering occur in plant propagation?

Layering is a method of plant propagation that occurs when a stem or branch of a plant makes contact with the ground or soil and develops roots while still attached to the parent plant. This technique takes advantage of the plant's natural ability to produce roots in response to environmental conditions, such as moisture and soil contact.

When a stem is bent to the ground and covered partially with soil, it can begin to produce roots, making it possible for a new plant to grow while remaining connected to the parent. This process is beneficial because it allows for the propagation of a genetically identical plant, ensuring consistency in traits. Ideally, once the new roots are established, the new plant can be severed from the parent and planted independently.

In contrast, planting seeds at a specific depth pertains to seed germination rather than layering, watering sufficiently relates more to nurturing established plants rather than propagating them, and grafting involves combining different plants to form a single individual rather than allowing one to root while attached. Thus, layering specifically refers to the rooting of stems in contact with soil.