Hun opbevarer frøene i en lille beholder til næste forår.

The normal order here is:

subject + finite verb + object + prepositional phrases/time phrase

So:

Hun + opbevarer + frøene + i en lille beholder + til næste forår

That is a very standard Danish main-clause pattern.

The infinitive is at opbevare. The form opbevarer is the present tense, and it is regular: many Danish verbs form the present by adding -r to the infinitive.

So:

• at opbevare = infinitive
• opbevarer = present tense

Because Danish usually adds the definite article to the end of the noun instead of using a separate word.

So frøene means the seeds, where the the idea is built into the ending. This is very common in Danish nouns.

It comes from et frø.

The forms are:

• et frø = a seed
• frøet = the seed
• frø = seeds
• frøene = the seeds

A useful thing to notice is that the indefinite plural is just frø, with no extra ending. That happens with some Danish nouns.

Because beholder is a common-gender noun, so it takes en, not et.

• en beholder = a container

If the noun were neuter, it would take et instead.

Lille is a somewhat special adjective. In the singular, it stays lille with both en and et nouns:

• en lille beholder
• et lille hus

So even though noun gender changes the article, lille itself does not change in this singular pattern.

I means in or inside. Since the seeds are physically stored inside the container, i is the natural preposition.

So i en lille beholder means that the seeds are located inside the container.

Here til most naturally means until. So the idea is that the seeds are being kept in the container until next spring.

Danish often uses til with a future point in time:

• til i morgen = until tomorrow
• til næste uge = until next week

In Danish, time expressions with words like næste, sidste, and denne usually do not take an article.

So Danish says:

• næste forår = next spring
• næste år = next year
• sidste uge = last week

That is normal Danish usage.

Yes, but Danish main clauses follow the verb-second rule. That means the finite verb usually stays in the second position.

For example, you could say:

I en lille beholder opbevarer hun frøene til næste forår.

This is still correct. The difference is that the place phrase is now emphasized, and because it comes first, the verb opbevarer must come before hun.