“Be careful what you water your dreams with”: did Laozi say it?
Not in the Dao De Jing
No: “Be careful what you water your dreams with” is not in the Dao De Jing; Wikiquote traces it to a 2004 business book, Inspired Wealth, by Aileen Miga and Janice Hughes.
Be careful what you water your dreams with.
Where it comes from
The passage is in no chapter of the Dao De Jing. It goes on to warn that worry and fear grow weeds and that optimism grows success. Wikiquote lists it among the sayings wrongly credited to Laozi and traces it to page 44 of Inspired Wealth: Financial Leadership for the 21st Century (2004) by Aileen Miga and Janice Hughes, a copy of which is on the Internet Archive, and dates the Laozi label to 2006 at the latest. We have not read that page ourselves. Stefan Stenudd, who keeps a list of sayings wrongly credited to Laozi, did not find the book; the earliest copies he found are a blog post and a Goodreads page of February 2008, both crediting Laozi.
Nothing like it in the Dao De Jing
The book never speaks of dreams, optimism or success in this sense, and no line comes close.