Short answer. The care of a good father of a family. Article 589 of the Civil Code requires the usufructuary to take care of the things given in usufruct as a good father of a family — the level of attentiveness a responsible, ordinarily careful person exercises over property in their charge, not an exceptional or extraordinary standard.
What the law says
The usufructuary shall take care of the things given in usufruct as a good father of a family.
Civil Code, Article 589 — The Standard of Care. Read the full provision →
What 'good father of a family' describes
Article 589's entire text is a single sentence: the usufructuary shall take care of the things given in usufruct as a good father of a family. "Good father of a family" is a traditional way of describing the diligence of a responsible, reasonably attentive person managing property that matters to them — not a careless custodian, but also not someone held to an exceptional or extraordinary level of vigilance. It sets a middle standard: real, active care, measured against what an ordinarily prudent person would do, rather than a stricter or more specialized benchmark.
The standard applies across the whole usufruct
Article 589 does not single out particular kinds of property or particular activities — storage, maintenance, ordinary use — for special treatment. It states the duty as a general standard covering the usufructuary's care of the things given in usufruct as a whole. That breadth means this article functions as a baseline obligation running through the entire relationship, rather than a rule limited to one specific situation.
What counts as falling short is not spelled out here
The article states the standard without listing examples of conduct that would or would not meet it. Whether leaving property exposed to an obvious risk, failing to perform routine upkeep, or some other specific choice by the usufructuary falls below the good-father-of-a-family standard is a factual question this article does not resolve for you. It tells you what level of care is owed; assessing whether particular conduct measured up to that level depends on the facts of the situation itself.
What Article 589 does not say about breach
This article establishes the duty itself; it does not, in its own text, spell out what happens if the usufructuary fails to meet it — whether that means paying for resulting damage, some other consequence, or a combination. Anyone concerned about a usufructuary's care falling short should not assume this article alone answers what follows from a breach; it fixes the standard of care owed, and the consequences of not meeting it are a separate matter this provision does not itself address.