Весной мама добавляет удобрение в почву, чтобы фикус рос лучше.

Весной is the instrumental singular of весна (spring).

In Russian, some seasons and times of day are commonly used in the instrumental case to mean during that time:

• весной = in spring
• летом = in summer
• осенью = in autumn
• зимой = in winter

So Весной мама добавляет... means In spring, Mom adds...

This is just a standard time expression, not an instrumental with the meaning by means of.

Добавляет is present tense, 3rd person singular, from добавлять.

Russian often uses the present tense to describe:

• habitual actions
• repeated actions
• general facts

So this sentence suggests something like a regular practice: In spring, Mom adds fertilizer to the soil...

It is not necessarily happening right this second. It can mean she does this in spring as a routine or general statement.

The verb добавлять is imperfective, while the perfective partner is usually добавить.

Here the imperfective is used because the sentence describes a repeated or general action, not one single completed event.

Compare:

• Мама добавляет удобрение... = Mom adds fertilizer / usually adds fertilizer
• Мама добавит удобрение... = Mom will add the fertilizer / will complete the act of adding

Since the sentence is about a general springtime habit, imperfective is the natural choice.

Yes, удобрение is the direct object of добавляет, so it is in the accusative case.

The noun удобрение is neuter and inanimate, and for many neuter inanimate nouns, the accusative singular looks exactly the same as the nominative singular:

• nominative: удобрение
• accusative: удобрение

So the form does not change, even though the case function does.

Because в почву expresses movement or direction into something.

Russian uses:

• в + accusative for motion/direction into
• в + prepositional for location inside

So:

• в почву = into the soil
• в почве = in the soil

Since fertilizer is being added into the soil, the accusative is used: в почву.

Почву is the accusative singular of почва (soil).

Because почва is a feminine noun ending in -а, its accusative singular usually changes -а to -у:

• nominative: почва
• accusative: почву

That is why the sentence has в почву.

Because чтобы introduces a subordinate clause of purpose.

The structure is:

• main clause: Весной мама добавляет удобрение в почву
• purpose clause: чтобы фикус рос лучше

Russian normally puts a comma before subordinate clauses introduced by words like что, когда, если, потому что, чтобы, etc.

So the comma here is required.

After чтобы, Russian often uses a verb form that looks like the past tense, but here it does not mean past time.

This construction expresses purpose, intention, or desired result:

• чтобы фикус рос лучше = so that the ficus would grow better / so that the ficus grows better

The form рос is historically the past tense form, but after чтобы it functions as part of a kind of subjunctive-style construction.

So do not read рос here as plain past grew. In this sentence, it means something like:

• so that it would grow better
• in order for it to grow better

Рос agrees with фикус, which is masculine singular.

The verb comes from расти (to grow). In this construction after чтобы, the form used is the masculine singular form:

• masculine: рос
• feminine: росла
• neuter: росло
• plural: росли

Since фикус is masculine, the sentence uses рос.

Because the idea is ongoing growth or improvement in growth, not a single completed result.

Расти is imperfective and refers to the process of growing. That fits well with лучше:

• чтобы фикус рос лучше = so that the ficus would grow better

A perfective verb would suggest a completed outcome, which is not the main point here. The sentence is about improving the plant’s ongoing growth.

Лучше here is an adverb, meaning better.

It modifies the verb рос:

• рос лучше = grew / would grow better

It does not describe the noun фикус directly. If you were describing the ficus itself with an adjective, you would need a different structure.

So here:

• фикус рос лучше = the ficus grew better / would grow better

Think of лучше as modifying how it grows.

Yes. Чтобы фикус рос лучше and чтобы фикус лучше рос are both natural.

The difference is mainly emphasis and rhythm:

• чтобы фикус рос лучше puts better at the end
• чтобы фикус лучше рос puts more focus on better before the verb

Russian word order is flexible, especially in subordinate clauses, as long as the grammar is clear.

Not naturally in this sentence, because the subject of the main clause and the subject of the purpose clause are different.

• Main clause subject: мама
• Purpose clause subject: фикус

When the subject is different, Russian normally uses a finite clause:

• чтобы фикус рос лучше

An infinitive after чтобы is more natural when the implied subject is the same as in the main clause, for example:

• Мама пришла, чтобы полить фикус. = Mom came to water the ficus.

Here, though, the one growing is the ficus, not the mother, so the finite clause is the right choice.

No, Russian word order is fairly flexible. This sentence starts with Весной to set the time frame first.

Other orders are possible, for example:

• Мама весной добавляет удобрение в почву...
• Мама добавляет удобрение в почву весной...

These can sound slightly different in emphasis, but the basic meaning stays the same.

Starting with Весной is very natural because it highlights when this happens.