Compassion literally means to feel with, to suffer with. Everyone is capable of compassion, and yet everyone tends to avoid it because it's uncomfortable. And the avoidance produces psychic numbing -- resistance to experiencing our pain for the world and other beings.
Gardening can provide an opportunity to slow down, be still, breathe, and connect with another form of life. For me, it is an experience of communion; I become one with this precious life in my garden, and it heightens my experience of love in the world. And that is what spirituality is all about: growing in love.