Years of dripping rain from these moss-soft trees, in an endlessly dank, chill climate, has tanned the leather of a cowl-cape worn by Pentecost, the gardener.  He tends the vast castle gardens with deep love and knowledge, and I liked the description of his attachment to plants: being moved more by their impulse to grow than by the result.    

See also a mossy metaphor by Henry Williamson.

‘It was strong and supple and had been stained and darkened by many storms and by the dripping of the rain from moss-gloved trees.’

Source: Mervyn Peake, Titus Groan, introduction by Anthony Burgess (London: Vintage Books, 1998), p. 86