Other sites you may be interested in :
National Gardens Scheme - to find gardens to visit
Blacksmiths Cottage Nursery - owned by the marvellous Ben Potterton!
Suffolk Gardens Trust - who conserve and protect Suffolk Gardens
Garden Organic - for organic gardening and the Heritage Seed Library
Buyrope - another organic site
and Wirefence - who have done the 'weeding' and found what they consider to be the best gardening sites on the Internet (pun intended!)