Balkondaki saksıları sularken kovayı yanlışlıkla devirdim.

balkondaki means the one(s) on the balcony or that are on the balcony.

It breaks down like this:

• balkon = balcony
• -da = in / on / at
• -ki = a suffix that turns the location phrase into something adjective-like

So:

• balkonda = on the balcony
• balkondaki saksılar = the pots on the balcony

In this sentence, balkondaki is describing saksıları.

Because balkondaki is being used to modify the noun saksıları.

Compare:

• Balkonda saksılar var. = There are pots on the balcony.
• Balkondaki saksılar = the pots on the balcony

So balkonda gives location for the whole clause, while balkondaki attaches that location to the noun itself.

In your sentence, the meaning is specifically the pots that are on the balcony.

Because it contains both the plural ending and the accusative ending:

• saksı = pot / flowerpot
• -lar = plural
• -ı = accusative case

So saksıları here means the pots as a specific direct object.

Turkish often marks a direct object with the accusative when it is definite or specific. So:

• saksılar sulamak would not fit this sentence
• saksıları sulamak = to water the pots

sularken means while watering.

The suffix -ken creates a time expression meaning while or when. It connects the two actions:

• watering the pots
• knocking over the bucket

So the sentence says that the bucket-knocking happened during the watering.

Both are possible in Turkish, but they are used a bit differently.

• sularken = while watering
• sulama sırasında = during the watering

sularken is more direct and verb-based. It sounds very natural when one action happens at the same time as another action.

So in this sentence, sularken is the most natural everyday choice.

Usually, yes.

In this sentence, the understood subject of both actions is I:

• I was watering the pots
• I knocked over the bucket

Turkish often leaves the subject unstated when it is clear from the verb ending and context.

Because the verb already shows it.

devirdim ends with -m, which marks first person singular in the past tense:

• devir-di-m
• knock over - past - I

So devirdim already means I knocked over. Adding ben is possible, but not necessary.

Because kovayı is also a specific direct object.

It breaks down like this:

• kova = bucket
• -yı = accusative

The y is a buffer consonant. Turkish uses it when a suffix beginning with a vowel is added to a word ending in a vowel.

So:

• kova
• kovayı = the bucket

yanlışlıkla means by mistake or accidentally.

It comes from:

• yanlış = wrong / incorrect
• yanlışlık = mistake
• -la = a suffix that can give a sense like with / by means of

So yanlışlıkla literally has the idea of through a mistake, but in natural English it is simply accidentally.

devirdim means I knocked over, I tipped over, or I overturned.

It comes from:

• devirmek = to knock over / tip over / overturn
• -di = past tense
• -m = I

So:

• devirdim = I knocked over

This verb is especially good for something that was standing upright and then got tipped over.

Because the meaning is slightly different.

• düşürmek = to drop / make something fall
• devirmek = to tip over / knock over something standing upright

A bucket is often standing on the ground, so devirmek is a very natural choice if you accidentally overturned it.

Because that is the normal Turkish pattern.

Turkish commonly puts the verb at the end, especially in neutral word order. So this sentence follows a very typical structure:

• location-based modifier
• object of the first action
• sularken clause
• object of the main action
• adverb
• main verb at the end

English and Turkish organize information differently, so this is a very common thing learners notice.

Yes, but changing it usually changes the emphasis, not the basic meaning.

For example, you could say:

• Kovayı balkondaki saksıları sularken yanlışlıkla devirdim.

That still means the same thing, but it puts more focus on kovayı.

The original version sounds natural and balanced.

It describes the pots.

The phrase balkondaki saksıları means the pots on the balcony.

So the balcony location is attached directly to saksılar, not to the speaker.

If you wanted to emphasize that you were on the balcony, Turkish would usually phrase that differently.