Etter hvert som plantene spirer, potter vi dem om.

In this sentence, etter hvert som means as or as ... gradually.

It introduces a process that happens little by little over time:

• Etter hvert som plantene spirer = as the plants sprout
• The idea is that the action in the main clause happens step by step while that process is unfolding.

A useful distinction:

• etter hvert on its own often means gradually / eventually
• etter hvert som
  • clause means as / as ... progresses

So here it suggests that the plants do not all sprout at exactly the same moment; when they do, they get repotted.

Because Norwegian follows the V2 rule in main clauses: the finite verb must come in the second position.

The sentence begins with a subordinate clause:

• Etter hvert som plantene spirer

After that, the main clause starts, and in the main clause the verb must come before the subject:

• potter vi dem om

So the structure is:

• [Subordinate clause], [verb] [subject] ...

Compare:

• Vi potter dem om etter hvert som plantene spirer.
• Etter hvert som plantene spirer, potter vi dem om.

Both are correct, but when the subordinate clause comes first, the main clause has inversion: potter vi.

Spirer is the present tense of å spire, which means to sprout, to germinate, or to begin growing.

So:

• å spire = to sprout
• spirer = sprout / are sprouting

In plantene spirer, it means the plants are sprouting or beginning to grow.

Å potte om means to repot — to move a plant into a new pot, usually a larger one.

In the sentence:

• potter vi dem om = we repot them

This is a verb + particle combination, where om is part of the expression. You should learn å potte om as a unit.

Other forms:

• å potte om
• jeg potter om
• vi pottet om
• vi har pottet om

Because å potte om is a phrasal/separable verb.

In infinitive form, the parts stay together:

• å potte om

But in a normal finite clause, the particle often comes later:

• Vi potter dem om
• Han pottet planten om

This is similar to separable verb patterns in other Germanic languages. The important thing is that om still belongs to the verb.

Because dem is the object form of the pronoun.

Here, plantene is the thing being repotted, so the pronoun is an object:

• plantene → dem
• potter vi dem om = we repot them

Very simply:

• de = they
• dem = them

So:

• De spirer. = They are sprouting.
• Vi potter dem om. = We repot them.

In some spoken Norwegian, people may use de and dem less strictly, but in standard written Bokmål, dem is the expected object form here.

Plantene means the plants.

Norwegian usually expresses definiteness by adding an ending to the noun:

• en plante = a plant
• planten = the plant
• planter = plants
• plantene = the plants

Here, plantene refers to specific plants already known in the situation — for example, the seedlings we are talking about.

If you said planter instead, it would mean plants more generally.

Yes, it is in the present tense, but that does not necessarily mean it is happening at this exact second.

Norwegian present tense is often used for:

• habits
• routines
• general procedures
• instructions
• things happening in an ongoing process

So Etter hvert som plantene spirer, potter vi dem om can mean something like a regular practice:

• As the plants sprout, we repot them

It sounds natural as a description of what we do whenever this stage is reached.

Because the sentence begins with a subordinate clause, followed by the main clause.

• Etter hvert som plantene spirer = subordinate clause
• potter vi dem om = main clause

In standard Norwegian punctuation, a comma is used between them when the subordinate clause comes first.

So the comma helps mark the boundary between:

1. the time/process clause
2. the main statement

Yes, that is grammatical, but the nuance is a little different.

• Når plantene spirer = when the plants sprout
• Etter hvert som plantene spirer = as the plants sprout / as they gradually sprout

Når is more neutral and just tells you when something happens.

Etter hvert som emphasizes a gradual process or things happening one by one over time.

So in this sentence, etter hvert som is a good choice if the plants sprout at different times and you repot them as that happens.

No. Here som is part of the fixed expression etter hvert som.

So it is not functioning like the som in a relative clause such as:

• planten som spirer = the plant that is sprouting

In your sentence, etter hvert som works together as a subordinating expression meaning as.

Inside that subordinate clause, the order is normal for a clause with a subject and verb:

• plantene = subject
• spirer = finite verb

So:

• Etter hvert som plantene spirer

Unlike the main clause, there is no inversion here after som. The inversion happens in the following main clause:

• potter vi dem om

So the full sentence shows two different patterns:

• subordinate clause: subject + verb
• main clause after fronting: verb + subject