What does 青々した mean?

[healer]

羊が青々した芝生を食べている。
Ref: FREE Japanese Word of the Day Widget - JapanesePod101

Is it derived from 青々する?
I don't see there is a suru form for this word in the dictionaries I use.
What is 青々として? They say 青々 is often written as 青々として.
The dictionaries say 青々 is green whereas 青 is green or blue. Is that correct?

 

[Toritoribe]

青々 is an adverb, and と is optional. 青々 can express the color green and blue, but it's more often used for the meanings "fresh" or "juicy", as in your example or 青々とした野菜.

 

[bentenmusume]

Well, it's listed as an adverb that can take する here:

「青々」の意味や使い方 わかりやすく解説 Weblio辞書

「青々」の意味は<p style="padding-bottom: 10px;"><!--AVOID_CROSSLINK-->読み方：あおあお<!--/AVOID_CROSSLINK-->いかにも青いさまのこと。Weblio国語辞典では「青々」の意味や使い方、用例、類似表現などを解説しています。

www.weblio.jp

As for 青々とした, that's just basically the way these adverbs connect to nouns as a relative clause. (Note that oftentimes the と is omitted, but this is also grammatical.)
「のんびり（と）した日常」「はっきり（と）した答え」, etc. etc.
(Note that する is in the perfect tense because the action is already complete and it's already in that state. I think that we discussed this before but feel free to ask for clarification if it doesn't make sense.)

If it were linking to a verbal predicate it would be 青々と, i.e. 芝生は青々と茂った.
のんびり（と）過ごした, etc.

There is some overlap traditionally between green and blue for 青.
In practice, 青々 seems often to be used to describe lush vegetation.

(edit: whoops, post overlapped with Toritoribe-san's. We're basically saying the same thing, so I'll leave my post intact.)

 

[Toritoribe]

FYI, the four colors 赤, 青, 黒 and 白 are special in Japanese. They are nouns, and also the stems of i-adjectives. Other colors don't have conjugation forms, but 黄色 and 茶色 are the only two exceptions. These colors can work as i-adjectives when used with 色.

○赤い 青い 黒い 白い
○黄色い 茶色い

×黄い 茶い 緑い 紫い 桃い
×緑色い 紫色い 桃色い

Incidentally, 赤, 青, 黒 and 白 have the same etymology with 明るい あかるい "bright", 淡い あわい "pale", 暗い くらい "dark" and 顕し しろし(obsolete) "clear/sharp", respectively, and these words have the similar adverb forms to 青々; 赤々 あかあか, 黒々 くろぐろ, 白々 しらじら/しろじろ, and 明々 あかあか, 淡々 あわあわ/たんたん, 暗々 くらぐら/あんあん.

 

[healer]

it's listed as an adverb that can take する

The translation doesn't mention anything that refers to する.
Does 青々した芝生 suggest the lawn being made green or lush?

I suppose 青々した芝生 is the exactly same as 青々とした芝生.
It seems to me you said と is always optional without changing the nuance or meaning.
It sounds like that is not only optional but redundant.

What could be difference if one says 青々芝生 or 青い芝生?
Oh! I've got "green grass" for the former but "blue grass" for the latter when I put them through Google Translate.
I know you told me not to use Google Translate. I just use it as one extra resource. I'm aware computerized translation without the human touch doesn't work.
It seems to me 青い tends to mean blue rather than green. The dictionaries I use say the same thing.
I understand 青々 tends to mean lush rather than green.

青々; 赤々 あかあか, 黒々 くろぐろ, 白々 しらじら/しろじろ, and 明々 あかあか, 淡々 あわあわ/たんたん, 暗々 くらぐら/あんあん

It seems to me where the adjective of single word repeating itself such as 青 -> 青々 the result becomes an adverb. Perhaps it might not always be true.

 

[Toritoribe]

The translation doesn't mention anything that refers to する.
Does 青々した芝生 suggest the lawn being made green or lush?

する doesn't always mean "to do" or "to make". 青々（と）した expresses a state here, meaning "(fresh) green", as in the given translation.

I suppose 青々した芝生 is the exactly same as 青々とした芝生.
It seems to me you said と is always optional without changing the nuance or meaning.
It sounds like that is not only optional but redundant.

Both are equally used, thus, it's not "redundant" at all. This is a fact whether you feel it's redundant or not. Sorry if this sounds harsh, but you seem to be baselessly confident with your own impression. Actually, it seems to me that you are just inexperienced.

What could be difference if one says 青々芝生 or 青い芝生?

青々芝生 is ungrammatical. 青々 is an adverb, as we already pointed out, thus, it can't modify a noun directly as same as もっと can't modify 人 or 水.

青い芝生 is valid. Have you never heard a proverb 隣の芝生は青い, which is the Japanese translation of "The grass is always greener on the other side of fence."?

It seems to me 青い tends to mean blue rather than green. The dictionaries I use say the same thing.

青 has a nuance of young, inexperienced, immature (e.g. 青二才, 青くさい, 青葉, 青年), similar to "green" in English. It doesn't always express only the color of the thing also in Japanese.

It seems to me where the adjective of single word repeating itself such as 青 -> 青々 the result becomes an adverb. Perhaps it might not always be true.

There are many those examples, and also many counterexamples.
e.g.
〇熱々 あつあつ
△冷々(ひえびえ exists, but it's usually written as 冷え冷え or ひえびえ)
〇寒々 さむざむ
×暑々
〇深々 ふかぶか
△浅々(obsolete)
〇近々 ちかぢか
△遠々(遠々し is obsolete, and 遠々 is not an adverb.)
〇早々 はやばや/そうそう
△遅々(The reading is ちち, not おそおそ)

 

[healer]

Sorry if this sounds harsh, but you seem to be baselessly confident with your own impression.

Sorry to say "redundant". I should have said different people express themselves in different style.

青々 is an adverb, as we already pointed out, thus, it can't modify a noun directly

So 青々（と）した is an adjective, isn't it?

 

[bentenmusume]

The phrase as a whole is a relative clause modifying a noun in the same way an adjective would, but that doesn't mean that (grammatically) it itself is an adjective.

Would you say 「昨日買った」 in 「昨日買った本」 is an adjective? No, and neither is this. Adjectives are not the only things that can modify nouns in Japanese grammar.