A fernery sounds great doesn’t it? Have to look into that! Good to hear you’ve had some success with one of those insect houses 👍I have a couple of insect houses. Last year one of them was occupied by solitary bees, it was fascinating watching them investigating the bamboo sticks to lay their eggs.
A fernery at the base of the wall sounds lovely, plenty of cover for frogs! They would make a nice background for flowering plants in the pond.