英語版FF9日誌117 : We were gonna put you to sleep with sleeping weed.

 Dagger:

Oh...um... How were you planning to abduct me?

Zidane:

We were gonna put you to sleep with sleeping weed, then kidnap you.  It's mostly used for kids, but a big dose can knock out an adult just as easily.

Dagger:

I guess you did't need it, since I came along on my own. Hey... Would you mind giving me some? I've had a hard time sleeping lately.

Zidane:

Um, I don't think that's a good idea. You might get addicted. Maybe all you need is some company, eh?

Dagger:

Oh, please. Do you think I'm that naive?

Zidane:

Heh, heh. Can't blame me for trying.

We were gonna put you to sleep with sleeping weed, then kidnap you.

put ~ to sleepで「眠らせる」という意味です。

動物を安楽死させる意味としても使われるようです。

FRIENDSという海外ドラマでも以下のセリフがありました。

It's like when you were a kid, and your parents put your dog to sleep and telling you it went off to live on some farm.