National Trust   Plenty of options here as with  English Heritage 

RHS Rosemoor. Depressingly superb   —   web site 

Castle Hill Gardens  —  web site 

Tapely Park House and Gardens   —  web site 

Marwood Hill Gardens   —  web site 

Stone Lane Gardens .  A very special garden (one of our favourites) featuring birch and alder trees and in the summer months a wonderful collection of garden sculptures for sale.  It is only only open in the afternoons but you can visit Castle Drogo  (NT) in the morning and have a pleasant lunch at The Sandy Park Inn which is between the two near Chagford. 

National Garden Scheme (Devon) - web site 

Powderham Castle near Exeter - web site  

The Garden House at Buckland Monachorum - Just south of Tavistock this is another favourite along with lunch at the very pleasant C16th Drake Manor Inn in the village. 

And just a mile down the road is the incomparable Wildside Garden open certain weekends through the year - check their website: www.wileyatwildside.com. A 'must' visit! 

Finally, whilst not really a garden, Lydford Gorge is well worth visiting for an extraordinary walk. Good walking shoes or boots and required and you may expect to see 4 foot wide butterflies and unicorns around every corner. It is really quite magical. And if you like good food then The Dartmoor Inn on the main road to Tavistock is another favourite. 

RHS Encyclopaedia Series including: 

Pruning by Christopher Brickell 

Veg Growing by Tony Briggs 

Organic Growing by Pauline Pears and Sue Stickland 

The New Kitchen Garden – Penelope Hobhouse 

Any books by Graham Stuart Thomas 

Chris Cork – All Seasons South West  

Trevor Andrews – North Devon Landscaping  

Millwood Plants 

Society of Garden Designers - I am currently a pre-registered member. 

Health Benefits of Gardening for Older Adults