What is the difference between these two groups?
Lots. The Royal Horticutural Society - horticulture - and the National Trust cares for historic old buildings.
but the national trust has some wonderful gardens
National trust = national treasures.
Gardens being more popular with visitors last year than houses with something like 70% of members signing up at gardens. How do I know this stuff?
Oh really. I guess we pick up all kinds of information and can never remember its true origins.
The RHS is a gardening charity intended to promote horticultural excellence and to disseminate information, advice, training and advice to gardeners both professional and amateur. It undertakes research into pests, diseases, best techniques, best plants and trains gardeners. It promotes gardening in schools, in the commnity and in private.
The National Trust is a charity devoted to preserving British heritage. It buys, or is bequeathed, historical houses of particular cultural or historic significance as well as gardens and landscapes which it works to maintain and preserve for posterity and in doing so keeps old crafts such as traditional carpentry and stone masonry and so on alive too..
Lovely and clear thank you very much Obelixx.