nedumari ga susumu ni turete, mizuhake ga waruku naru.

In this sentence, 根詰まり（ねづまり） is a gardening term meaning a plant’s roots have become too crowded in the pot or soil, so they are packed together and have little room to spread.

In English, this is often described as being root-bound or pot-bound.

So 根詰まりが進む means something like:

• the root-bound condition gets worse
• the roots become more crowded
• root congestion progresses

This is different from some other words with 詰まる / 詰まり, which can mean to be clogged or to be blocked in other contexts.

Because the sentence has two parts, and each part has its own subject:

1. 根詰まりが進むにつれて
   → root crowding progresses

2. 水はけが悪くなる
   → drainage becomes worse

In Japanese, the subject of each clause can be marked with が.

So this is not strange or repetitive. It is just:

• 根詰まり is the thing that progresses
• 水はけ is the thing that becomes worse

〜につれて means as..., in proportion as..., or along with....

It shows that one change happens gradually together with another change.

So:

• 根詰まりが進むにつれて
  = as root crowding progresses = the more root-bound it becomes, the worse...

This pattern is often used when two things change together over time.

Examples:

• 年を取るにつれて、体力が落ちる。
  As I get older, my physical strength declines.
• 季節が変わるにつれて、気温も下がる。
  As the season changes, the temperature also falls.

Because 〜につれて attaches to the dictionary form of a verb in this kind of sentence.

So:

• 進む → dictionary form
• 進むにつれて → as it progresses

You do not use 進んでにつれて here.

This is a standard grammar pattern:

• Verb dictionary form + につれて
• Noun + にしたがって / とともに can sometimes express similar ideas, but につれて is especially common with gradual change.

Because 悪い is an i-adjective, and when an i-adjective comes before なる, its 〜い changes to 〜く.

So:

• 悪い → bad
• 悪くなる → become bad / get worse

This is the normal rule for i-adjectives:

• 高い → 高くなる
  become expensive / become high
• 寒い → 寒くなる
  become cold
• 悪い → 悪くなる
  become bad / worsen

水はけ（みずはけ） means drainage, especially how well water drains from soil, a pot, or some other material.

It literally comes from the idea of water passing through / draining away.

So:

• 水はけがいい = drains well
• 水はけが悪い = drains poorly

In this sentence, 水はけが悪くなる means:

• the drainage gets worse
• water stops draining as well as before

Yes. Both are fine depending on how natural you want the English to sound.

Possible translations include:

• the drainage becomes poor
• drainage gets worse
• it drains less well
• the soil/pot drains poorly
• water drainage worsens

In natural English, drainage gets worse or it drains less well often sounds better than a very literal translation.

Literally, it is something close to that, but in natural English you usually would not say root clogging progresses.

Japanese often uses 進む with conditions or processes to mean:

• advance
• progress
• become more severe
• develop further

So 根詰まりが進む is more naturally understood as:

• the root-bound condition worsens
• the roots become increasingly crowded
• root congestion progresses

Because Japanese often leaves out information that is understood from context.

If you are already talking about a plant in a pot, then the sentence does not need to repeat:

• the plant
• the pot
• the soil

So the sentence can simply say:

• As root crowding progresses, drainage gets worse.

In Japanese, omitted subjects and topics are very common when they are obvious from context.

No, it is not strictly necessary, but it is helpful.

The comma after につれて makes the sentence easier to read by separating:

• the dependent clause: 根詰まりが進むにつれて
• the main clause: 水はけが悪くなる

So it is mainly a readability choice.

Without the comma, the meaning stays the same:

• 根詰まりが進むにつれて水はけが悪くなる。

All three can mean something like as... or along with..., but there are slight differences.

〜につれて

• often emphasizes a gradual change
• very common when one thing changes in step with another

〜にしたがって

• also means as / according to / in accordance with
• can sound a bit more formal or objective
• often used for changes that follow a pattern

〜とともに

• means together with
• can sound more formal or written
• may be used for simultaneous change, but not always as specifically gradual as につれて

In this sentence, につれて fits very naturally because root crowding and poor drainage increase together over time.

Yes, but the nuance changes a little.

〜と often sounds more like:

• when X happens, Y happens
• a general consequence or natural result

〜につれて sounds more like:

• as X gradually changes, Y gradually changes too

So:

• 根詰まりが進むと、水はけが悪くなる。
  = When root crowding progresses, drainage becomes worse.
• 根詰まりが進むにつれて、水はけが悪くなる。
  = As root crowding progresses, drainage gets worse.

The second one better expresses a gradual relationship, so it is a very good choice here.