“Right plant in the right place” (or “right plant, right place”) is a popular landscaping adage of unknown authorship. “Plant trees and be sure they are planted right, planted in the right place and that the right varieties are planted” was cited in 1902. “Right plant in the right place” was cited in 1905. “Artistic gardening consists in putting the right plant in the right place” was cited in 1907.
 
Nicola Ferguson’s book, Right Plant, Right Place, was first published in 1984 and had a new edition in 2005.
 
 
Chronicling America
11 March 1902, The Daily Ardmoreite (Ardmore, OK), pg. 4, col. 2:
Here is a little piece of good seasonable advice right now, plant trees and be sure they are planted right, planted in the right place and that the right varieties are planted.
 
Google Books
Journal of the Royal Horticultural Society
Volume 29
1905
Pg. 595:
THE LAWS OF DEVELOPING LANDSCAPE
By J. FORSYTH JOHNSON
(...)
This is accomplished by developing character with suitable association, and putting the right plant in the right place.
 
Google Books
Beautiful Gardens:
How to Make and Maintain Them
By Walter Page Wright
London: Cassell and Company, Limited
1907
Pg. 7:
Artistic gardening consists in putting the right plant in the right place, and growing it properly when you have got it there!
   
Google Books
March 1909, Better Fruit, “Some Important Notes on Small Fruits” by J. O. Holt, pg. 31, col. 3:
When the right man puts the right plant in the right place the result will spell success.
 
September 1914, Suburban Life (The Countryside Magazine), “Making a Success of Tree Planting” by Floyd S. Platt, pg. 135, col. 2:
JUST as it has been stated that it is important to get the right plant in the right place, so also it is important to plant your trees and shrubbery at the right time, in order to secure satisfactory results.
 
Google Books
April 1915, The National Nurseryman (Rochester, NY), “The Nurseryman as a Landscape Gardener,” pg. 139, col. 1:
After all good gardening consists of putting the right plant in the right place. and giving it the right attention when you have got it there.
 
OCLC WorldCat record
Right plant, right place
Author: Nicola Ferguson; Fred McGourty
Publisher: New York : Summit Books : Distributed by Simon and Schuster, ©1984.
Edition/Format:   Print book : English
Database: WorldCat
Summary:
“Over 1,500 garden plants are systematically organized according to growing conditions, purpose, and appearance.”—Cover.
 
OCLC WorldCat record
Right plant, right place
Author: Cheryl Maddocks
Publisher: Sydney : Doubleday, 1995.
Edition/Format:   Print book : English
 
OCLC WorldCat record
Right plant, right place
Author: Jackie Matthews
Publisher: London : Southwater, 2001.
Edition/Format:   Print book : English
 
OCLC WorldCat record
400 trees and shrubs for small spaces : [how to grow the right plant in the right place]
Author: Diana Miller
Publisher: Portland : Timber Press, 2008.
Edition/Format:   Print book : English
 
Twitter
Santa Cruz Sentinel
‏@scsentinel
Tom Karwin, On Gardening: During drought, remember—right plant in right place http://dlvr.it/9Qpbq3
9:39 PM - 16 Apr 2015