木は

tree; as for the tree

→ 木
phrase Common #6,713
tree; as for the tree 木 means a tree growing in the ground. は marks it as the topic of the sentence; depending on context, 木 can refer to one tree or trees in general.
JA: この木は赤くて綺麗ね。
EN: This tree is red and beautiful.

木はその実によってわかる。

A tree is known by its fruit.

そして、木はたびたび一人ぼっちになりました。

And the tree was often left all alone.

この木はあの木とほぼ同じ高さだ。

This tree is about the same height as that one.

木は一本も見えなかった。

There wasn't a single tree in sight.

木はその実で分かる。

A tree is known by its fruit.

これらの木は彼らの植えたものだ。

These trees were planted by them.

緑の木は…どうかお願いです

The green tree is... please, I’m begging you.

— ミッション・クレオパトラ (2002)

多くの木は冬になると葉がなくなる。

Many trees lose their leaves in winter.

木はまもなく葉が落ちるだろう。

The trees will soon lose their leaves.

金のなる木はないんだよ。

There’s no such thing as a money tree.

私の木は少し花をつけたが実はならなかった。

My tree produced a few flowers, but no fruit.

木は果実を見ればわかる。

A tree is known by its fruit.