One of the best things you can do for hedgehogs is make sure your boundary is permeable.
My neighbours recently replaced their fence and while the new one looks better and isn't likely to come down in a storm it also has concrete posts and gravel boards so hedgehogs have no chance to roam over the area they need :-(
P.S. I've also bought as many plants as I can that are either friendly to insects - lavender and buddleias and the like - but also plants known to attract slugs. I don't really want ornamental plants eaten by slugs, but at least it'll make the garden a feast for hungry hedgehogs.
One of the best things you can do for hedgehogs is make sure your boundary is permeable.
My neighbours recently replaced their fence and while the new one looks better and isn't likely to come down in a storm it also has concrete posts and gravel boards so hedgehogs have no chance to roam over the area they need :-(