La bandeja de germinación está junto al semillero.

Because bandeja is a feminine noun in Spanish, so it takes the feminine article la.

A good rule is:

• nouns ending in -a are often feminine
• nouns ending in -o are often masculine

So:

• la bandeja = the tray

As always, grammatical gender does not necessarily mean the object is feminine in any real-world sense. It is just part of the noun’s grammar.

De germinación describes what kind of tray it is.

So:

• bandeja = tray
• bandeja de germinación = germination tray / seed-starting tray

This is a very common Spanish pattern:

• X de Y = X of Y or X for Y, depending on context

Examples:

• mesa de madera = wooden table
• taza de café = coffee cup
• bandeja de germinación = germination tray

In Spanish, this structure is often preferred where English might use a noun as an adjective.

Because the sentence gives the location of something, and in Spanish, location is usually expressed with estar, not ser.

So:

• está junto al semillero = it is next to the seedbed/seedling tray

A key rule:

• ser is generally for identity, origin, characteristics, time, etc.
• estar is generally for location and states/conditions

Examples:

• Es una bandeja de germinación. = It is a germination tray.
• Está junto al semillero. = It is next to the seedbed/seed tray.

Junto a means next to, beside, or right by.

In this sentence:

• junto al semillero = next to the seedbed / beside the seedling tray

It is a very common way to express physical proximity.

Related expressions:

• al lado de = next to / beside
• cerca de = near
• junto a = right next to / together with / beside

Depending on context, junto a can sometimes also mean together with, but here it clearly indicates location.

Because a + el contracts to al in Spanish.

So:

• junto a + el semillero → junto al semillero

This contraction is mandatory in standard Spanish.

The two main contractions you should know are:

• a + el = al
• de + el = del

Examples:

• Voy al jardín. = I’m going to the garden.
• La tapa del frasco. = The lid of the jar.

Important: this only happens with el, not with la, los, or las.

• junto a la mesa = correct
• not a contraction

Semillero can refer to a place or container where seeds are sown and begin to grow.

Depending on context, it may be translated as:

• seedbed
• seed tray
• seedling tray
• nursery bed

In gardening vocabulary, the exact English translation can vary. The important idea is that it is a place for starting plants from seed.

It comes from semilla = seed.

Because in the phrase bandeja de germinación, germinación is part of a descriptive de phrase, and Spanish often does not use an article there.

So:

• bandeja de germinación = germination tray

Compare:

• centro de salud = health center
• clase de español = Spanish class
• proceso de germinación = germination process

If you added an article, it could change the meaning or make it sound more specific:

• la bandeja de la germinación would sound unnatural in this context

Yes. Al lado de is a very common alternative to junto a.

So these are both natural:

• La bandeja de germinación está junto al semillero.
• La bandeja de germinación está al lado del semillero.

Both mean that the tray is next to the seedbed/seedling tray.

A small nuance:

• junto a can sound a little more direct or formal in some contexts
• al lado de is extremely common in everyday speech

A simple pronunciation guide is:

her-mee-nah-SYON in much of Latin America

More carefully:

• ger ≈ her
• mi = mee
• na = nah
• ción = syon

The stress falls on the last syllable because of the written accent:

• ger-mi-na-CIÓN

Also note:

• in most of Latin America, c before i or e sounds like s
• so -ción sounds like syon, not thyon

Yes, but the original order is the most neutral and natural.

Standard order:

• La bandeja de germinación está junto al semillero.

You could also say:

• Junto al semillero está la bandeja de germinación.

That version is grammatical, but it sounds more marked or descriptive, as if you are emphasizing the location first.

For learners, the original word order is the safest choice.

Yes.

Singular:

• la bandeja de germinación

Plural:

• las bandejas de germinación

And the verb changes too:

• La bandeja de germinación está junto al semillero.
• Las bandejas de germinación están junto al semillero.

Notice:

• bandeja → bandejas
• está → están

But germinación stays singular here because it is part of the type/name of the object, not something being counted separately.