The following is a quote from 'The Pocket Thich Nhat Hanh' (click)
and published by 'Shambhala Pocket Classics'.
TOUCHING THE EARTH
"With the earth you are very safe.
She is always there, in all her wonderful expressions like trees,
flowers, butterflies, and sunshine.
Whenever you are tired or unhappy,
Touching the Earth is a very good practice to heal you and restore your joy."