園 in Chinese / Japanese...

園 is a single character that means garden in Chinese, Japanese Kanji, and old Korean Hanja.

This can also mean an orchard or park.

園 is not a common single character for a wall scroll but nothing is wrong with it. A lot of customers asked for a single character for a garden, so I've provided what I think is the best option here.

禪園 literally means “meditation garden.”

The first character happens to be known as Zen in the west (the pronunciation comes from Japanese) but this title is not often used in Japan (won't be recognized as a Japanese title).

The title “Zen Garden” was made up by westerners I'm afraid.

島成園 is the name Shima Seien (1892–1970), a nihonga artist in Taishō and Shōwa Japan.

天真武芸学園 is the title for Tenshin Bugei Gakuen in Japanese Kanji.

花園里的戰士好過戰場上的園丁 is the Chinese for the phrase, “It is better to be a warrior in a garden than a gardener in a war.”

This proverb is purported to come from the following exchange:

A student approaches his samurai master and says,
“Teacher, you instruct me how to fight, yet you preach to me about peace. How do I reconcile the two?”
The samurai responds,
“Because it is better to be a warrior in a garden than a gardener in a war.”

This is Tao Yuanming's poem, “Returning to Dwell in Gardens and Fields.”

少無適俗韻 性本愛丘山。
誤落塵網中 一去三十年。

羈鳥戀舊林 池魚思故淵。
開荒南野際 抱拙歸園田。

方宅十餘畝 草屋八九間。
榆柳蔭後簷 桃李羅堂前。

暖暖遠人村 依依墟裡煙。
狗吠深巷中 雞鳴桑樹顛。

戶庭無塵雜 虛室有餘閒。
久在樊籠裡 復得返自然。