arraigar

To take root — literally, of a plant, and very commonly figuratively, of a person settling somewhere or a custom/belief becoming firmly established (una tradición muy arraigada, a deeply rooted tradition). Also a legal/immigration term (arraigo) for ties that let someone regularize their status.

• El árbol tardó años en arraigar en ese suelo pobre. — The tree took years to take root in that poor soil.
• Después de una década, la familia ya se había arraigado en la ciudad. — After a decade, the family had already put down roots in the city.
• Es una costumbre muy arraigada en la región. — It's a deeply rooted custom in the region.

Confusing arraigar (to take root, settle, become established over time) with radicar (to be located/situated) — arraigar implies a gradual process of becoming rooted, not simply being somewhere.