Revisé el cepellón cuando el esqueje empezó a enraizar.

Because Spanish often leaves out subject pronouns when the verb already makes the subject clear.

• Revisé already means I checked / I inspected
• So yo is unnecessary unless you want emphasis or contrast

For example:

• Revisé el cepellón = I checked the root ball
• Yo revisé el cepellón, no Ana = I checked the root ball, not Ana

In a neutral sentence like this one, leaving out yo sounds completely natural.

Revisé is the preterite, which is used for a completed action in the past.

Here, the speaker is talking about one specific action:

• I checked the root ball

So revisé fits well.

If you said revisaba, that would sound more like:

• I was checking
• I used to check
• an ongoing or habitual background action

Compare:

• Revisé el cepellón cuando el esqueje empezó a enraizar.
  = one completed check at that moment

• Revisaba el cepellón mientras el esqueje enraizaba.
  = I was checking it while the cutting was rooting

In gardening, cepellón refers to the root ball: the mass of roots and soil attached to a plant when it is removed from a pot or the ground.

It is more specific than just raíces (roots) or tierra (soil).
So el cepellón means the whole compact root-and-soil mass.

This is a fairly specialized gardening word, but it is the natural term in this context.

Spanish uses the definite article very often when talking about specific things already understood in the situation.

Here, both are specific:

• el cepellón = the root ball being discussed
• el esqueje = the cutting being discussed

In English, you might sometimes say the, or sometimes leave things more implicit. Spanish tends to use the article more consistently.

Also, both nouns are masculine:

• el cepellón
• el esqueje

This is a very common structure in Spanish:

empezar + a + infinitive

It means to start / begin to do something.

So:

• empezó = started / began
• a enraizar = to take root / to root

Together:

• empezó a enraizar = started to take root

You can use the same pattern with many verbs:

• Empezó a llover = It started to rain
• Empecé a estudiar = I started studying
• La planta empezó a crecer = The plant started to grow

Because this sentence refers to a real, completed event in the past.

When cuando refers to something that actually happened, Spanish uses the indicative:

• cuando el esqueje empezó a enraizar

If the event is in the future or has not happened yet, Spanish normally uses the subjunctive:

• Cuando el esqueje empiece a enraizar, revisaré el cepellón.
  = When the cutting starts to take root, I’ll check the root ball.

So:

• past, real event -> indicative
• future or pending event -> subjunctive

In this context, enraizar is normally used without a reflexive pronoun.

• El esqueje empezó a enraizar = natural and standard

For plants or cuttings literally taking root, the non-reflexive form is the usual choice.

You may occasionally see reflexive or other related verbs in different contexts, but for gardening Spanish, enraizar is the most straightforward and natural form here.

Yes. That version is completely correct.

Spanish allows flexible word order, especially with time clauses like cuando...

Both are natural:

• Revisé el cepellón cuando el esqueje empezó a enraizar.
• Cuando el esqueje empezó a enraizar, revisé el cepellón.

The difference is mostly one of emphasis:

• starting with Revisé... emphasizes the main action
• starting with Cuando... sets the time frame first

Revisar means more than just to look at. It usually means:

• to check
• to inspect
• to examine

So revisé el cepellón suggests a deliberate inspection.

By contrast:

• mirar = to look at
• ver = to see
• comprobar = to verify / check

In this sentence, revisé is a good choice because it suggests the speaker examined the root ball to see its condition.

In standard Peninsular Spanish:

• cepellón -> roughly the-pe-YON
• esqueje -> roughly es-KE-he
• enraizar -> roughly en-rai-THAR

A few useful pronunciation points:

• ce is often pronounced like th in think in most of Spain
• j sounds like a strong, throaty h
• z is also often pronounced like th in most of Spain
• ll is often pronounced like y in modern Spanish, though this varies by region

These English-style approximations are not exact, but they are a good start.

They show which syllable is stressed, and they are also part of the correct written forms of these verbs in the preterite.

• revisé -> stress on the last syllable
• empezó -> stress on the last syllable

These endings are very common in the preterite:

• -é for yo with -ar verbs
  
  • revisé, hablé, miré
• -ó for él/ella/usted with -ar verbs
  
  • empezó, habló, miró

The written accent is important because it helps distinguish forms. For example:

• revisé = I checked
• revise = a different form, such as a subjunctive or formal command depending on context

So the accents are not optional; they are part of the grammar.