La horticultura urbana utiliza semillas locales.

In Spanish, nouns often use the definite article more often than in English.

Here, la horticultura means urban horticulture as a general field or activity. Spanish commonly says la + noun when talking about something in a general or abstract way.

• La horticultura urbana utiliza semillas locales.
• Literally: The urban horticulture uses local seeds.
• Natural English: Urban horticulture uses local seeds.

So the article is normal in Spanish, even when English would often leave it out.

Because horticultura is a feminine noun in Spanish. Most nouns ending in -a are feminine, and this is one of them.

That is why it uses:

• la horticultura
• horticultura urbana

The adjective must match the noun’s gender, so urbana is feminine singular to agree with horticultura.

Adjectives in Spanish usually agree with the noun they describe in gender and number.

Since horticultura is:

• feminine
• singular

the adjective must also be:

• feminine
• singular

So:

• horticultura urbana = correct
• horticultura urbano = incorrect

Because the subject of the sentence is la horticultura urbana, which is singular.

The verb utiliza is the third-person singular form of utilizar in the present tense.

• yo utilizo = I use
• tú utilizas = you use
• él/ella/usted utiliza = he/she/you use

Even though semillas is plural, that does not affect the verb, because semillas is the object, not the subject.

Utilizan is the third-person plural form, so it would need a plural subject.

For example:

• Los agricultores utilizan semillas locales. = The farmers use local seeds.

But in your sentence, the subject is singular:

• La horticultura urbana utiliza...

So utiliza is the correct form.

Spanish often leaves out the article when talking about things in a general, indefinite sense.

Here, semillas locales means local seeds in general, not specific seeds already identified.

So:

• utiliza semillas locales = uses local seeds

If you said utiliza las semillas locales, it would sound more like:

• uses the local seeds
• meaning specific local seeds that both speaker and listener know about

In Spanish, most descriptive adjectives come after the noun.

So:

• semillas locales = local seeds
• agricultura urbana = urban agriculture
• productos ecológicos = ecological products

This is one of the big differences from English, where adjectives usually come before the noun.

Because semillas is plural, so the adjective must also be plural.

• singular: semilla local = local seed
• plural: semillas locales = local seeds

Local is one of those adjectives that has the same form in masculine and feminine singular:

• producto local
• semilla local

But in the plural, it becomes:

• productos locales
• semillas locales

They are very similar, but utilizar is often a little more formal or technical than usar.

So:

• La horticultura urbana utiliza semillas locales.
• La horticultura urbana usa semillas locales.

Both are correct and natural.
Utiliza may sound slightly more formal, academic, or explanatory, which fits a sentence like this well.

Yes, it is in the present tense.

Here, the present tense expresses a general truth or a habitual practice, not something happening only right now.

So the sentence means something like:

• Urban horticulture uses local seeds
• Urban horticulture tends to use local seeds

This is very common in Spanish, just as in English:

• El agua hierve a 100 grados.
• La agricultura ecológica evita ciertos productos.

In normal Spanish, no. That would sound very unnatural here.

The usual order is:

• la horticultura urbana

Putting the adjective before the noun is possible with some adjectives in some contexts, but it is much less common and often changes the tone or style. With urbana, the normal and expected position is after the noun.

A Spain Spanish approximation is:

or-ti-kool-TU-ra

A few key points:

• The h is silent.
• The c before u sounds like k.
• The stress falls on tu: horticultúra.

And for the whole sentence, roughly:

La or-ti-kool-TU-ra oor-BA-na oo-ti-LEE-tha se-MEE-yas lo-KA-les

In much of Spain, z in utiliza sounds like the th in think.
In Latin America, it is usually pronounced like s.

Here is the breakdown:

• La — definite article, feminine singular
• horticultura — noun, feminine singular
• urbana — adjective, feminine singular, describing horticultura
• utiliza — verb, present tense, third-person singular
• semillas — noun, feminine plural
• locales — adjective, plural, describing semillas

So the structure is:

article + noun + adjective + verb + noun + adjective

More or less, yes, but the result may sound slightly unnatural in English.

Word-for-word:

• La = the
• horticultura = horticulture
• urbana = urban
• utiliza = uses
• semillas = seeds
• locales = local

So:

• The urban horticulture uses local seeds

But more natural English would usually be:

• Urban horticulture uses local seeds

This is a good example of how Spanish and English often express the same idea with slightly different article usage.