- Gregg Gardens.
- Gregg, Bobibt E
- Gregg, Clifford C., 1895-1992
- Gregg, Edward J.
- Gregg, James H
- Gregg, John R
- Gregg, Josiah, 1806-1850
- Gregg, Kenneth W
- Gregg, Michael A
- Gregg, Robert E. (Robert Edmond), 1912-1991
- Gregg, Robert Edmond, 1912-1991
- Gregg, S. A.
- Gregg, Thomas.
- Gregg, W. H.
- Gregg, Wendell O
- Gregg, William H.
- Grego, Christiana Kelly da Silva
- Grego, Joseph, 1843-1908
- Grego, Jozef
- Grégoire, Charles 1907-
- Gregoire, David P.
- Grégoire, Jean-Claude
- Gregor, Hans-Joachim
- Gregori, Carlo Bartolomeo, 1702-1759
- Gregoric, Diego E Gutiérrez
- Gregoric, Diego Eduardo Gutiérrez
- Gregorič, Matjaž
- Gregorich, L. J.
- Gregorin, Renato
- Gregorini, Armando
- Gregorio, Antonio de.
- Gregório, Bernarda
- Gregório, E. A. (Elisa Aparecida)
- Gregorio, Josefat Gregorio
- Gregorio, Marchese Antonio Di
- Gregorio, Pablo
- Gregorio, Patrícia L. F. (Patrícia Luciane Fernandes)
- Gregorio-Jáuregui Karla M.
- Gregorová, Růžena
- Gregory Farm.
- Gregory N.Stephanopoulos Aristos A.Aristidou Jens Nielsen
- Gregory Nursery Co.
- Gregory Seed Company.
- Gregory, Augustus Charles 1819-1905
- Gregory, Beau B.,
- Gregory, Chas. T. 1887-
- Gregory, Constantine
- Gregory, Daniel R.
- Gregory, David
- Gregory, David A.
- Gregory, David P. (David Palache)
- Gregory, Emily L.
- Gregory, Frank H.
- Gregory, Frederick Gugenheim 1893-1961
- Gregory, G. (George), 1754-1808
- Gregory, G. Robinson, 1915-
- Gregory, Herbert E. (Herbert Ernest), 1869-1952
- Gregory, J E
- Gregory, J. E.
- Gregory, J. W. (John Walter), 1864-1932
- Gregory, J.J.H. & Son.
- Gregory, Jacqueline
- Gregory, James F.
- Gregory, James J. H. (James John Howard), 1827-1910
- Gregory, Jeren
- Gregory, John L.
- Gregory, Joseph Tracy, 1914-
- Gregory, Joseph Tracy, 1914-2007
- Gregory, Lee V
- Gregory, Linda A.
- Gregory, Louise H
- Gregory, M. Mathews
- Gregory, Mark
- Gregory, Mark S.
- Gregory, Mary
- Gregory, Michael J.
- Gregory, Neil
- Gregory, Olinthus, 1774-1841
- Gregory, Patrick T.
- Gregory, Phil (Bird watcher)
- Gregory, Philip Herries.
- Gregory, R A
- Gregory, R. A.
- Gregory, R. A. (Robert Aaron)
- Gregory, R. P.
- Gregory, Richard, Sir, 1864-1952
- Gregory, Robert S.
- Gregory, Roger W.
- Gregory, Shari
- Gregory, Steve J
- Gregory, Steven D
- Gregory, Steven M S
- Gregory, Ted
- Gregory, Timothy J
- Gregory, Tremaine
- Gregory, W. B. (William Benjamin), 1871-
- Gregory, William K. (William King), 1876-1970
- Gregory, William, 1803-1858
- Grego-Valencia, Dalia
- Gregson, Jo
- Gregson, John D.
- Gregson, Margaret M.
- Gregson, Robert A M
- Gregurke, John
- Gregurke, John E
- Grehan, Anthony J
- Grehan, John R.
- Gréhant, Nestor, 1838-1910
- Greif, Matthew
- Greif, Roger L
- Greifeneder, Dietmar
- Greig, Edward R
- Greig, John, active 1803-1853
- Greig, Nancy
- Greig, W A
- Greigg's Dahlia Gardens.
- Greig-Smith, Robert
- Greil Bro's Company.
- Greilach, Hugo
- Greiman, Stephen E.,
- Greimler, Josef
- Greinberg, Reinhold.
- Greiner & Pfeiffer,
- Greiner, Ellis C.
- Greiner, Gary O. G.
- Greiner, Hugo Robert,
- Greiner, J.
- Greiner, Tuisco, 1846-1914
- Greismer, J. W.
- Greizerstein, Eduardo
- Greke, Kristine
- Grekul, Chad
- Grela, Iván A.
- Grelen, Harold Eugene, 1929-
- Grell, E. H., 1932-
- Grell, Olaf
- Grelle, Carlos E. V.
- Greller, Andrew M
- Grellet-Tinner, Gerald
- Grémare, Antoine
- Gremillion, Kristen J
- Gremli, A. (August), 1833-1899
- Grempel, Renato Grotta
- Gremski, Waldemiro
- Grenacher, H. (Hermann), 1843-1923
- Grenand, Pierre
- Grenard, Fernand, 1866-1942
- Grende, E
- Grenell, Robert G. (Robert Gordon), 1916-
- Grenell, W. H.
- Grenet, Armand.
- Grenfell, Hugh R
- Grenfell, Margaret
- Grenfell, Wilfred Thomason, Sir, 1865-1940
- Grenha, Viviane
- Grenier, M. (Charles), 1808-1875
- Grenier, Diane
- Grenier, Ève-Lyne
- Grenier, Nickolas P
- Grenot, Claude
- Grenside, F. C.
- Grentzenberg, M.
- Grenzebach, Myrle
- Greppi, Emanuele
- Greppi, Julian
- Greš, Stanislav
- Grès, Virginie
- Gresham College.
- Gresham Nurseries.
- Gresham, A. B.
- Gresham, Belinda
- Gresham, Burt
- Gresham's Nursery,
- Greshoff, M. 1862-1909
- Greslebin, Alina G
- Gress, Ernest Milton 1876-1968
- Gress, Franklin
- Gresser, Edward B
- Gressitt, J. Linsley
- Gressler, Daniel T.
- Gressler, Eliana
- Gressler, Luciane T.
- Gressler, Pablo
- Gressner, Heinrich
- Gresswell, Albert
- Gresswell, Charles.
- Gresswell, Dan Astley 1853-1904
- Gresswell, George, 1858-1914
- Gresswell, James Brodie.
- Gresswell, Robert E.
- Gretchina, Alexandre
- Greth, Arnaud
- Grether & Son.
- Grether Gonzalez, Rosaura
- Grether, Gregory F
- Gretton, Adam
- Greulach, Victor A
- Greuter, Johann Friedrich, 1590-1662
- Greuter, Mark Walter, 1930-2017
- Greuter, Mathieu, 1564?-1638
- Greuter, Werner
- Grevé, Carl
- Greve, Caroline
- Greve, John H
- Greve, Karl, 1854-
- Greve, Lita
- Grève, Pierre
- Greve, W., lithographer.
- Greven, Hartmut
- Grever, Michael R
- Greville, Robert Kaye, 1794-1866
- Grévin, Jacques, 1538?-1570
- Grew, David.
- Grew, Edward W.
- Grew, Edwin Sharpe, 1867-
- Grew, Joseph Clark.
- Grew, Nehemiah, 1641-1712
- Grewal, G S
- Grewal, Jasjit Singh 1951-
- Grewe, Felix
- Grey of Fallodon, Edward Grey, Viscount, 1862-1933
- Grey Owl, 1888-1938
- Grey, Alexandra
- Grey, Darryl L.
- Grey, E C
- Grey, Earl
- Grey, Ed
- Grey, Edwin.
- Grey, Jonathan
- Grey, Lionel Paul
- Grey, M.
- Grey, Marion
- Grey, Merilyn J
- Grey, Pat
- Grey, Robert
- Grey, Thomas J. & Co.
- Grey, W.
- Grey, Zane, 1872-1939
- Greyes, Natch
- Grez, Audrey A.
- Grez, Daniel Barros
- Grez, Vicente
- Grgurinovic, Cheryl Anne 1958-
- Gribben, Paul E.
- Gribble Nurseries.
- Gribble, James.
- Gribble, Neil A.
- Gribel, Rogério
- Gribelin, Simon, 1661 or 1662-1733
- Gribodo, Giovanni