What does this quote mean: “Every blade of grass has its angel that bends over it and whispers, 'Grow, grow.'”?

Awwwww...sweet. Here are some similar ones for you.

"Great is the human who has not lost his childlike heart." Mencius

"An eye for an eye will make the whole world blind" Author Unknown

Keep love in your heart. A life without it is like a sunless garden when the flowers are dead. The consciousness of loving and being loved brings a warmth and richness to life that nothing else can bring.

Oscar Wilde

Here's to a long life and a merry one

A quick death and an easy one

A pretty girl and an honest one

A cold beer and another one!

Irish Saying

The goal of life is living in agreement with nature.

Zeno

From Diogenes Laertius, Lives of Eminent Philosophers.

Life is far too important a thing ever to talk seriously about.

Oscar Wilde

Lady Windermere's Fan, Act I.

Where there is love there is life.

Indira Gandhi

To succeed in life, you need three things: a wishbone, a backbone and a funnybone.

Reba McEntire

"A man's real worth is determined by what he does when he has nothing to do." Author Unknown

"It is not the answer that enlightens, but the question." Eugene Ionesco

The last one reminds me of Y!A, hahaha

It means every living thing is special and, if you believe in god and god's responsibility for the creation of all life, then each thing has an angel to encourage and watch over it.

"God's eye is on the sparrow" is a similar quote meaning no one or no thing is too small or insignificant in the eyes of god.