Letters from Harvey J. Sims to horticulturists at the Department of Agriculture Central Experimental Farm in Ottawa, with replies from M.B. Davis, Dominion Horticulturist, T.F. Ritchie, Chief Assistant, and R.W. Oliver, Assistant (ornamental horticulture) as well as to Leonard S. McLaine at the Destructive Pest and Insect Advisory Board. The correspondence relates primarily to Harvey's collection of shrubs and trees, and his pursuit of adding more species to his collection. He mentions that he has collected 76 of the 82 native trees listed in Forest trees of Ontario, also that he has between 500 and 600 different varieties of trees and shrubs. He requests specimens for testing hardiness, also sends an unknown specimen for identification, and requests information on permits necessary to import nursery specimens from the Arnold Arboretum in Jamaica Plains, New York.

Correspondence from and to Harvey J. Sims and various nurseries and seed and plant suppliers relating to plants, trees, and shrubs for his property. Includes catalogues, lists and invoices. Suppliers include The Brampton Nursery, Cedarvale Tree Experts, Depuys and Ferguson (Montreal), Dominion Seed House, Endean Nurseries (Richmond Hill), Herbst Brothers (New York). More suppliers can be found in Series 8, Harvey J. Sims : Personal Business.

Correspondence from and to Harvey J. Sims and Alfred Rehder, Curator of the Herbarium at The Arnold Arboretum, Jamaica Plains, New York, attempting to identify specimens Harvey is sending.

Correspondence from and to Harvey J. Sims and J.H. White, University of Toronto, author of Forest Trees of Ontario. Includes pencil notes and lists by Harvey, information about Tree Tanglefoot and an envelope labelled "Address – Forest Trees" containing pencilled notes by Harvey for a speech about the importance of forest trees.

Correspondence from and to Harvey J. Sims and Arthur Gilbey, Nursery Sales Manager, Nursery Stock, at E.D. Smith and Sons, Winona, Ontario.

Correspondence from and to Harvey J. Sims and H.D. Smith, K.C., R.A. McLaren, and Charles C. Bell in Chatham, Ont. about sourcing and procuring seedlings of specific native trees and shrubs found at Rondeau Park and vicinity.

Correspondence from and to Harvey J. Sims and various book dealers and publishers relating to Harvey's efforts to build his library collection: Albert Britnell Book Shop (Toronto), The Book Society, World Books, Old Authors Shop (Ottawa), The Narrator (January 1942), Toronto Book Fair, Creasser's Book Shop (Toronto), T. Eaton Co. and the John Hardwick Co. (The Book House for Children). Includes invoices, catalogues, book lists, reviews, periodical issues and ephemera.

Correspondence from and to Harvey Sims and Arthur Herbert Richardson at the Ontario Department of Lands and Forest concerning reforestation efforts at Chicopee. In 1940, Harvey writes that he has more than 700 varieties of trees and shrubs, including all but 5 of the 82 native forest trees listed by J.H. White in Forest Trees of Ontario. In 1930, he writes that the Boy Scouts and Rotarians propose helping him plant 3500 more trees on Chicopee heights to complete the work started in 1929.

Correspondence from and to Harvey J. Sims, Adam Strohm, Librarian at the Detroit Public Library, and Charles R, Sanderson, Chief Librarian of the Toronto Public Library, between 1927 and 1941, the latter two often enclosing each other's letters. Adam Strohm sometimes encloses letters from Fred Burden, a mutual friend of his and Harvey's. Harvey had initially approached Adam Strohm for advice about books for his library; this correspondence included Sanderson after 1927. As well as corresponding about books these three men developed a friendship demonstrated in their letters, writing about their visits, their travels, and their lives.

Letters (approximately 16) between members of the Arthur Forbes Nicol and Harvey J. Sims families from 1928 to 1941. Harvey J. Sim's wife Florence Katherine Roos and Arthur F. Nicol's wife Florence Helen Kempt were first cousins: their mothers were sisters Elizabeth and Margaret Davidson. Letters concern mutual interests, politics and family.

Correspondence to and from Harvey J. Sims and Carl A. Borgstrom, landscape architect mostly concerning trees and shrubs for Harvey's property.

Correspondence to and from Harvey J. Sims and Carl A. Borgstrom of Carl Borgstrom & H.S.M. Carver, Landscape Architects and Town Planners, relating to nursery stock supplied through Lorne Park Nurseries. Includes a hand-drawn orchard plan.

Correspondence to and from Harvey J. Sims (carbons), relating to ongoing work at Chicopee, such as the pergola, log cabin, frog fountains, plantings, trees, and shrubs, and problems with wiring for road lights and flood lights. Includes detailed lists of nursery stock. Correspondents include Carl A. Borgstrom, Ball Brothers, Lorne Park Nurseries, A.H. Tomlinson (Department of Horticulture, University of Guelph), and the Mattell & Bierwagen Electric Company.

Correspondence to and from Harvey J. Sims (carbons), tenders, agreements, invoices and other material relating to work being planned and carried out at Chicopee, including landscape features, nursery stock, concrete bridge, bubbling tanks, dry stone walls, also to a Workmen's Compensation case. Correspondents include Ball Bros., Dunker Brothers, Herbert Johnston, Civil Engineer, Forsey Page & Steele, architects, Fess Oil Burners of Canada Ltd., Thomas Rennie, Ontario Agricultural College, Carl A. Borgstrom (of Wilson, Bunnell & Borgstrom Ltd., also of Lorne Park Nurseries) landscape architect.

Correspondence relating to Chicopee: recommendation from William Rennie Seed Co., Nov. 1, 1928, that Harvey contact Arthur E.K. Bunnell of Wilson Bunnell & Borgstrom, Landscape Architects for designing his grounds, and Lt. Col. Sandford F. Smith "would be better to consult regarding your house."
Includes two letters from Forsey Page & Steele, December 14 and 29, regarding drawing up plans for the house, and one submission from Bell Telephone for supplying telephone service.

Correspondents include the Canadian Legion, Canadian Kennel Club, A. Chappell concerning Chicopee Heights, Ernest and Alice Chadwick, Hector Charlesworth, Chicopee Tennis Club, Chicopee Ski Club, and E.H. Coleman.

Correspondence from Harvey Sims' old friend Fred C. Burden, also a friend of Adam Strohm, from whom there are several letters mixed in this file. Places written from range from Detroit, Michigan, where Fred lived for some time, to California.

Typewritten letter from Carl A. Borgstrom, landscape architect, to Harvey J. Sims, expressing gratitude to Harvey for his assistance in arranging for him to be able to visit Kingsmere, and enclosing a copy of the letter he had written to Mackenzie King with thanks for putting his name before the National Employment Commission.

Includes invitation to the Cook family reunion, correspondence about peafowl and other wild stock available, and a postcard showing Hialeah Park Race Track, Florida.

Includes correspondence to and from Harvey J. Sims concerning placing his son at a law firm, also a letter from Florence M. Austin, Nov. 30, 1938, Dousman, Wis., on the genealogy of the Cook family and their mutual relationship.