In this photo you can see that on top, and in the cavities, leaves etc. can easily fall and remain . This then becomes the compost in which new plants can grow. They are also interesting places for insects and birds. Both are therefore abundant.
thanks for explaining Ferry. Is soil added inside these cavities? or is it left naturally for leave etc to fall in?
I love the idea that flowers etc grow from here
Ian
I love the idea that flowers etc grow from here