An example for live fence is

An example of a live fence is agave.
Agaves are sturdy, architectural plants that provide a visually stimulating and low-maintenance, presence of spines on each leaf end, it is most commonly used as a live fence.
Live or bio fencings are lines of trees or shrubs planted on farm or field boundaries that provide protection against cattle and wildlife, act as windbreaks, enrich the soil, provide bee forage, provide shade and control dust.