These are the plants I’ve chosen to “fence” Quemao Viejo. Better than steel or walls, I’ll plant these, which could at the same time produce food, medicinal uses, wood and coverage for wild fauna.
Blackberry (Rubus fruticosus). It grows quickly and nearly in any kind of soil; easy to propagate ( considered an invasive plant); delicious berries; tea with the leaves; many medicinal uses and the hedges it forms are basically impenetrable.
Common Hawthorn ( Crataegus monogyna).
It tolerates poor soils and grows quickly ( invasive plant in some parts of the world) with a chance to be used for wood production, its berries and leaves are edible; medicinal uses ( cardiac insufficiency) and its branches are armed with thorns.
Opuntia ( Opuntia ficus-indica).
They are cactus plants, so they need little water to survive. They are one of the most easily propagated plants ( I have seen the leaves cut out from the plant, and grow roots after been abandoned in the soil. Its “leaves” ( the real leaves are evolved into the thorns of the plant) can be eaten as vegetable/fruit or to make jam. Their sap can be used in bio-construction ( applied over mud to make it waterproof). All that without forgetting the delicious fruits, the prickly pears.
Wild rose ( Rosa canina).
Maybe the weakest choice here, but it is already present in the land and it’s propagation seems quite easy ( at least there are about twenty thousand million books about rose propagation! ) Its flowers and fruits are edible ( maybe not directly but jams can be made). The vitamin C content of the fruit is five times bigger than in a lemon!