I weekenden vil vi plante frø i fugtig jord bag huset.

Because Danish often puts a time expression first when it sets the scene.

• I weekenden = at the weekend / on the weekend
• It tells us when the action happens.

Putting the time first is very common in Danish:

• I dag arbejder jeg hjemme. = Today I’m working from home.
• I morgen kommer de. = Tomorrow they are coming.

In this sentence, I weekenden is placed first for natural emphasis on the time.

In Danish, many time expressions use i, even where English might use on or at.

So:

• i weekenden = at/on the weekend
• i morgen = tomorrow
• i sommer = in the summer / this summer

You usually just have to learn which preposition Danish prefers. Here, i is the normal choice.

The -en is the definite article added to the noun.

• en weekend = a weekend
• weekenden = the weekend

Danish usually puts the at the end of the noun instead of using a separate word like English does.

So:

• I weekenden literally looks like in the weekend
• but the natural English meaning is at/on the weekend

This is because Danish follows a verb-second (V2) rule in main clauses.

When something other than the subject comes first, the finite verb must come second.

Here the order is:

1. I weekenden
2. vil
3. vi
4. plante frø ...

So:

• Vi vil plante frø i weekenden. = neutral order
• I weekenden vil vi plante frø. = time comes first, so the verb moves before the subject

This is one of the most important Danish word-order patterns to learn.

Not always. Vil can mean:

• will for future
• want to / intend to, depending on context

In this sentence, vil vi plante frø most naturally means:

• we will plant seeds or
• we’re going to plant seeds

It can sound a little like intention as well, which is normal in Danish.

Because it comes after vil, and after modal verbs like vil, Danish uses the infinitive.

So:

• vil plante = will plant
• kan plante = can plant
• skal plante = must / will plant

The infinitive in Danish often ends in -e, and here that form is plante.

Here frø means seeds, so it is plural.

A tricky point is that frø can look the same in singular and plural in some contexts:

• et frø = a seed
• frø = seeds

So the sentence means plant seeds, not plant a seed.

Because the sentence is talking about seeds in a general sense, not specific seeds already known to the listener.

So:

• plante frø = plant seeds
• plante et frø = plant a seed
• plante frøene = plant the seeds

English does the same thing quite often:

• We will plant seeds not necessarily
• We will plant the seeds

Because jord here is being used as an uncountable material noun, like soil in English.

So:

• i fugtig jord = in moist soil

You would not normally say:

• i en fugtig jord for this meaning

Compare:

• vand = water
• sand = sand
• jord = soil/earth

These often appear without an article when speaking generally about the substance.

Adjectives in Danish change form depending on the noun.

Here:

• jord is a common-gender noun: en jord in theory, though usually used as an uncountable noun
• so the adjective takes the common-gender/basic form: fugtig

Compare:

• fugtig jord = moist soil
• fugtigt vejr = moist/damp weather
  because vejr is a neuter noun

So the adjective form matches the noun type.

Bag huset means behind the house.

• bag = behind
• huset = the house

Again, Danish usually puts the at the end:

• et hus = a house
• huset = the house

So bag huset is literally behind the house.

Because Danish usually uses the suffixed definite article for a simple definite noun.

So:

• et hus = a house
• huset = the house

You use det hus more in special situations, for example for emphasis or when adding a following description:

• det store hus = the big house
• det hus, vi købte = the house that we bought

But in bag huset, the normal form is just huset.

Because i can mean different things depending on context.

In this sentence:

• I weekenden = at/on the weekend → time expression
• i fugtig jord = in moist soil → location/medium

This is very common in Danish. A single preposition can cover several meanings that English may express with different prepositions.

Yes, that is also grammatical.

The difference is mainly focus:

• I weekenden vil vi plante frø i fugtig jord bag huset.
  Emphasizes when
• Vi vil plante frø i fugtig jord bag huset i weekenden.
  Starts more neutrally with we

Both are natural. Danish word order is flexible, but moving an element to the front changes what gets highlighted.

These can be hard for English speakers.

• frø contains ø, a vowel that does not exist in standard English
• fugtig also has a tricky vowel and a soft, reduced ending in normal speech

Helpful points:

• ø is a rounded front vowel; learners often approximate it poorly at first, and that is normal
• frø is a very short word, and the vowel quality matters a lot
• fugtig may sound less clearly pronounced than its spelling suggests in fast speech

If you are learning pronunciation, ø is one of the sounds worth practicing separately.

A useful breakdown is:

• I weekenden = time
• vil = finite/modal verb
• vi = subject
• plante = infinitive
• frø = object
• i fugtig jord = prepositional phrase
• bag huset = location

So the full pattern is:

Time + finite verb + subject + infinitive + object + place

That makes this sentence a very good example of normal Danish main-clause word order with a fronted time expression.