The Wildlife Trusts is the official face of what is, in effect, like a confederation of independent states: the various county wildlife trusts. Many, if not all, of the county wildlife trusts have their own websites and you can reach them via links from the Wildlife Trusts' website. Some county trusts seem to be more involved in wildlife gardening initiatives than others, but there can be no doubting the importance given to the subject by the trusts as a whole when you consider the track record of the Wildlife Trusts.
The Wildlife Trusts have either been involved in, or entirely responsible for, the publication of some of the most important books on the subject (e.g. Fran Hill's Wildlife Gardening
and Chris Packham's Back Garden Nature Reserve
For information of wildlife gardening, go to the homepage, and navigate to UK Wildlife>People and Wildlife