Expressing intervals of time, and AからBすると

Question

Referring to cherry blossoms:

咲き始めてから１週間から１０日ぐらいすると、たくさん花が咲いてきれいです。
After they start to bloom, from one week ???? lots of flowers will bloom and (look) pretty.

I'm struggling to understand the part in bold. If I read it literally I get "When it makes around 10 days from/after a period of one week". Logically, therefore I get "Lots of flowers will bloom around 17 (10+7) days after they first start". Obviously I think my analysis is nonsense.

My guess is that it reads "Lots of flowers will bloom after a period of around 7 to 10 days from when they first start". Is this correct? Is there a way to break it down logically?

More generally what are the common ways to express an interval of time after which something will happen? I would have tried something like:

7日と10日ぐらいのあいだに

but that feels incomplete. It seems to be lacking the idea of later. I know I can says "2 days later" as 2日後に. I guess "around 2 days later" would be 2日後ぐらいに, but I expect 7日と10日後ぐらいのあいだに is completely wrong.

Answer 1

「咲{さ}き始{はじ}めてから[１週間]{いっしゅうかん}から[１０日]{とおか}ぐらいすると、たくさん花{はな}が咲{さ}いてきれいです。」

I will start with the word that you did not even mention -- 「する」.　In this context, it means "to pass"; It is often used to express the passing of a specific length of time. Whether or not one actually uses the verb "to pass" in one's translation is a totally different matter. Personally, I would not.

Next, the 「と」 is conditional, of course. Again, that does not mean one should use "when" or "if" in one's translation. I would not use it.

「Time Length + ぐらい + する + と」

means:

"within approximately (time length)"

In this case, the time length mentioned happens to have a range of 一週間 to １０日. 「から」 can singlehandedly express a temporal or spatial "range". I mention this because there might be people who thought that 「から」 could only be used to describe a starting point.

Thus, my own TL of 「１週間から１０日ぐらいすると」 would be:

"within approximately a week to 10 days"

Being a Japanese-speaker, I have no idea where you would get the idea of "17 (7 + 10) days", but I can assure you that that is not what 「１週間から１０日」 means regardless of the context that the phrase appears in.

(You mentioned 「7日と10日ぐらいのあいだに」, but if someone said that to me, I would probably think he was trying to say "between the 7th and 10th of a certain month".)

The key word here is 「から」 for expressing a range. 「と」 seems quite out of place to my Japanese-speaking brain. I could not use a 「と」 if I had to rephrase 「１週間から１０日ぐらい」. It can be rephrased to 「７日から１０日ぐらい」, using 「一週間」 would sound more natural.

"Within approximately a week to 10 days after they start blooming, they will bloom in abundance and look beautiful."