الشتلة هتكبر طول ما التربة رطبة.

Because الشتلة is a feminine singular noun in Arabic, so the verb has to agree with it.

• هتكبر = it will grow for a feminine singular subject
• هيكبر would be used with a masculine singular subject

So:

• الشتلة هتكبر = The seedling will grow
• If the subject were masculine, like الزرع in some contexts, you might get هيكبر

In Egyptian Arabic, this تـ in the verb is what marks feminine singular in this kind of future form.

The هـ is a very common Egyptian Arabic future marker. It means will / going to.

So:

• تكبر = she/it grows or she/it grows regularly / grows
• هتكبر = she/it will grow

This is one of the easiest ways to form the future in Egyptian Arabic.

Examples:

• هاروح = I will go
• هتنام = you will sleep
• هتكبر = it will grow

In Egyptian speech, this future هـ is much more common than the MSA-style سـ.

طول ما means as long as in this sentence.

So:

• الشتلة هتكبر طول ما التربة رطبة = The seedling will grow as long as the soil is moist

It can also sometimes feel close to while, depending on context, but here as long as is the best match because it expresses a condition.

A useful way to think about it:

• طول ما + clause = as long as / while

Examples:

• هستناك طول ما إنت فاضي = I’ll wait for you as long as you’re free
• طول ما الجو حلو، هنخرج = As long as the weather is nice, we’ll go out

Because in Arabic, in the present tense, you usually do not use a word equivalent to is/am/are in simple statements like this.

So:

• التربة رطبة literally looks like the soil moist
• but it means the soil is moist

This is completely normal in Arabic.

Compare:

• البنت تعبانة = The girl is tired
• المية ساقعة = The water is cold
• التربة رطبة = The soil is moist

If you wanted was or will be, then Arabic would normally use a verb, but for simple present is, it is usually omitted.

Because التربة is a feminine noun, and the adjective has to agree with it.

• التربة = feminine
• so the adjective becomes رطبة = moist (feminine)

Compare:

• جو رطب = humid weather / the weather is humid
  (جو is masculine)
• تربة رطبة = moist soil
  (تربة is feminine)

This kind of adjective agreement is very important in Arabic:

• masculine noun → masculine adjective
• feminine noun → feminine adjective

It is understandable and correct, but it can sound a bit formal or educated compared with some everyday alternatives.

In everyday Egyptian Arabic, people might also say things like:

• الأرض = the ground / soil
• الطينة = the soil / clay-like earth in some contexts

So depending on the situation, you might hear:

• الشتلة هتكبر طول ما الأرض رطبة
• or more colloquially something with مبلولة or ندية instead of رطبة

But التربة is still a good word, especially in agricultural, scientific, or instructional language.

رطبة is correct and clear, but in everyday speech, Egyptians may sometimes prefer other words depending on the exact meaning:

• رطبة = moist
• مبلولة = wet
• مبتلة = wet / damp (a bit more formal)
• ندية = moist / slightly damp, often a nice match for soil that should not be dry

So if you are talking about gardening, something like this may sound very natural too:

• الشتلة هتكبر طول ما التربة نديّة
• الشتلة هتكبر طول ما الأرض مش ناشفة

The original sentence is perfectly fine, but there are several natural ways to express the same idea.

A natural pronunciation would be approximately:

ish-shatla hatikbar tool ma it-torba ratba

A few notes:

• الشتلة → the ال becomes pronounced like the following sh sound, so you get something like ish-shatla
• هتكبر → often hatikbar or hatikbar
• التربة → usually something like it-torba
• رطبة → ratba

So the whole sentence flows roughly as:

ish-shatla hatikbar tool ma it-torba ratba

Exact pronunciation varies a bit by speaker and region, but that is a good learner-friendly version.

Because both ش and ت are sun letters, so the ل in ال is not pronounced clearly. Instead, it assimilates to the next consonant.

So:

• الشتلة is pronounced roughly ash-shatla / ish-shatla
• التربة is pronounced roughly at-torba / it-torba

You write ال normally, but in speech the l sound disappears before sun letters.

This happens in both Standard Arabic and Egyptian Arabic.

Yes. That would be completely natural.

You could say:

• الشتلة هتكبر طول ما التربة رطبة
• طول ما التربة رطبة، الشتلة هتكبر

Both mean essentially the same thing.

The difference is mostly about emphasis:

• starting with الشتلة هتكبر emphasizes the result: the seedling will grow
• starting with طول ما التربة رطبة emphasizes the condition: as long as the soil is moist

Arabic is often flexible about this kind of word order.

It is a mix that leans Egyptian in structure, but some vocabulary feels a bit more formal.

What sounds Egyptian:

• هتكبر with هـ for the future is very Egyptian
• طول ما is also very common in Egyptian

What feels a bit more formal or neutral:

• التربة
• رطبة

So the sentence is perfectly understandable and good Arabic, but if you wanted it to sound more everyday Egyptian, you might hear something like:

• الشتلة هتكبر طول ما الأرض نديّة
• الشتلة هتكبر طول ما التربة مش ناشفة

The original version is still very useful, especially for learners.

Yes. الشتلة usually refers to a young plant, especially one that has been planted or is ready to be planted.

Depending on context, English translations could include:

• seedling
• sapling
• young plant
• transplant in some agricultural contexts

So seedling is a very good translation here, but not always the only possible one.

The structure is:

[subject] + [future verb] + [condition introduced by طول ما]

So here:

• الشتلة = subject
• هتكبر = future verb
• طول ما التربة رطبة = condition clause

You can think of it as:

• The seedling will grow
• as long as the soil is moist

That makes this a very useful pattern to remember:

• X هيحصل / هتعمل... طول ما...
• X will happen / you will do... as long as...

Example:

• هتعرف تشتغل طول ما عندك كهربا
  = You’ll be able to work as long as you have electricity