Website/Catalog  (13 Dec 2021)  
 
https://www.familytreecircles.com/bulla-blackwood-and-alister-clark-s-roses-vic-aust-and-cornwall-and-heronswood-61641.html

In a recent issue of The Blackwood Times, Blackwood historian,Margot Hitchcock, wrote an article about Matthew Rogers, the first or early owner of the land on which the Garden of St Erth was developed. Matthew, whose huge angel-topped monument is easily the most prominent in the Blackwood cemetery, was born in St Erth, Cornwall. 
The same issue (and article?),probably Oct-Nov 2014,discussed the Garnett family's tenure at the Garden of St Erth. 
The following website unfortunately does not indicate when the Diggers' Club was established.....

Magazine  (2020)  Page(s) 17. Vol 42, No. 4.  
 
Tiffany would like to acknowledge the generosity of other members who have given her
unusual heritage roses to add to her collection. “Their roses would probably be some
of my more cherished specimens. Such as…..and “Garden of St Erth” from Bonita Cattell.”
 

Magazine  (2018)  Page(s) 56. Vol 40, No. 2.  
 
Bonita Cattell This is a list of the cutting grown roses we had for sale: 
Mrs Harold Brocklebank, Peace 1902, Madame Berkley, Duchess de Brabant, Pink Maman Cochet, Snow Spray, Prosperity, Bloomfield Abundance, "Garden of St Erth". The proceeds were shared with the Horticulture Stewards to enable them to purchase more trophies for Heritage

Book  (2011)  
 
Castlemaine 1991 Conference.  Tommy Garnett, the great old gardener and writer who developed the garden from St Erth at Blackwood in Victoria, dealt with the life of Alister Clark and his garden at Glenara.
 

Magazine  (2010)  Page(s) 20. Vol 32, No. 4.  
 
Sue Zwar  After the conference we spent a couple of days with good friends, Ron and Hazel Treloar, in their new home at Cooroy.   Ones that took my eye…..“Garden of St. Erth” a ‘found’ rose with lovely dainty trusses of semi-double cupped pink and white blooms.