Foråret er den årstid, hvor blomsterne kommer frem i haven.

It is the noun forår meaning spring, plus the definite ending -et.

• forår = spring
• foråret = the spring / spring

Forår is a neuter noun, so its definite singular ending is -et.

It is capitalized only because it is the first word of the sentence.

In Danish, nouns are not generally capitalized the way they are in German. So in the middle of a sentence, you would normally write foråret, not Foråret.

Because årstid is a common-gender noun, so it takes den, not det.

This can be confusing because the first part, år, is a neuter noun. But in Danish compounds, the gender usually comes from the last part of the compound:

• år = year
• tid = time
• årstid = season

Since tid is common gender, årstid is also common gender. So:

• en årstid
• den årstid

Because the noun is being followed by a describing clause: hvor blomsterne kommer frem i haven.

In Danish, when a noun is specified by something like an adjective or a relative clause, it is very common to use the separate definite article den/det/de plus the noun in its basic form:

• den årstid, hvor ...

This is similar to how Danish says:

• den store bil = the big car

rather than attaching the definite ending directly to the noun.

Here hvor introduces a relative clause and means something like when or in which.

So:

• den årstid, hvor blomsterne kommer frem i haven means
• the season when the flowers come out in the garden

Even though hvor often means where, with words for time it can also mean when.

Blomsterne is the definite plural form of blomster.

• en blomst = a flower
• blomster = flowers
• blomsterne = the flowers

In this sentence, Danish refers to the flowers as a known set, namely the flowers in the garden. English might sometimes use just flowers in a general sense, but Danish often prefers the definite form in this kind of context.

Kommer frem is a verb phrase that literally means something like come forward or come out, but here it means appear, emerge, or start showing.

With flowers, it suggests that they begin to come up or become visible in spring.

So blomsterne kommer frem is a natural way to say that the flowers come out or start appearing.

Because hvor blomsterne kommer frem i haven is a subordinate clause, not a main clause.

In Danish main clauses, the finite verb usually comes in second position. But after words like hvor, at, fordi, and similar subordinators, Danish uses subordinate-clause word order.

So this is normal:

• hvor blomsterne kommer frem

not:

• hvor kommer blomsterne frem

The second version would sound like a question, not a relative clause.

Because i is the normal preposition for something happening in a garden.

• have = garden
• haven = the garden

So:

• i haven = in the garden

For an ordinary garden, i is the natural choice. English speakers sometimes overthink prepositions here, but this one is fairly straightforward.

Haven is the definite singular form of have.

• en have = a garden
• haven = the garden

Have is a common-gender noun, so its definite singular ending is -en.

Not in the same way.

Here hvor connects back to the noun årstid and introduces a relative clause:

• den årstid, hvor blomsterne kommer frem i haven

If you used når, it would no longer work as a relative clause attached to årstid in the same natural way. Når is mainly used for time clauses meaning when in the sense of at the time that:

• Når blomsterne kommer frem, er det forår.
• When the flowers come out, it is spring.

So both words can relate to time, but they do different jobs in the sentence.

Yes, fairly literal.

Word for word, it is close to:

• Foråret = Spring
• er = is
• den årstid = the season
• hvor = when / in which
• blomsterne kommer frem = the flowers come out / appear
• i haven = in the garden

So the overall sentence structure is actually quite friendly for an English speaker. The main differences are:

• Danish definite endings: foråret, blomsterne, haven
• the use of den årstid before a relative clause
• hvor being used where English prefers when