- Howard, William Johnston
- Howard, William Travis, 1867-
- Howard/Stein-Hudson (Firm)
- Howard-Hickory Co.
- Howard-Hickory Company.
- Howard-Jones, Norman.
- Howard-Looney, Melissa
- Howards Of Hemet,
- Howard's Strawberry Fields (Firm)
- Howarth, Brigitte
- Howarth, David A.
- Howarth, Francis G., 1940-
- Howarth, Graham
- Howarth, Henry H.,
- Howarth, J. A. (John Albert), 1893-
- Howarth, Jamie
- Howarth, Jamie D.
- Howarth, M K
- Howarth, Michael Kingsley
- Howarth, Osbert John Radcliffe, 1877-1954
- Howarth, T G
- Howarth, Thomas Graham
- Howat, I
- Howat, Irene
- Howat, M. G.,
- Howatson, T. M.
- Howchin, Walter
- Howcroft, J
- Howcroft, N H S
- Howd, Peter A.
- Howden, A T
- Howden, Anne T
- Howden, Henry F. (Henry Fuller) 1925-2014
- Howden, Mark
- Howden, Peter.
- Howe & Stanfield.
- Howe Gardens,
- Howe Nurseries.
- Howe, Amanda K
- Howe, Andrew Jackson, 1825-1892
- Howe, Andy G.
- Howe, Bruce M.
- Howe, Carlton D.
- Howe, Caroline G
- Howe, Clifton D. (Clifton Durant), 1874-
- Howe, E C
- Howe, E. W. (Edwin Walter), 1901-
- Howe, Elliot Calvin, 1828-1899
- Howe, Emery Lewis.
- Howe, Eugene W.
- Howe, Frances S.
- Howe, Frank E.
- Howe, Frederic Clemson, 1867-1940
- Howe, G. H. 1888-
- Howe, George F.
- Howe, George Plummer, 1879-
- Howe, Georgiana Lakin.
- Howe, H V
- Howe, Hamilton & Grant.
- Howe, Henry F.
- Howe, Henry V
- Howe, Henry V. (Henry Van Wagenen), 1896-
- Howe, Inez Addie
- Howe, James M. Jr.
- Howe, John A
- Howe, Joseph, 1804-1873
- Howe, M A
- Howe, M Dorisse
- Howe, Malverd Abijah, 1863-
- Howe, Marshall A. (Marshall Avery), 1867-1936
- Howe, Natalie M.
- Howe, Nathan R
- Howe, O. R., Jr.,
- Howe, Octavius T. 1851-
- Howe, P A W
- Howe, P E
- Howe, Ralph Wesley, 1889-
- Howe, Reginald Heber
- Howe, Reginald Heber, Jr. 1875-1932
- Howe, Review By: Marshall A
- Howe, Ric
- Howe, Richard W
- Howe, S W
- Howe, W. E.
- Howe, Walter,
- Howe, Walter, 1848?-1890
- Howe, William Norton.
- Howe, William, 1620-1656
- Howell Gardens,
- Howell Nurseries (Nashville, Tenn.)
- Howell Nurseries.
- Howell Nursery (Semmes, Ala.),
- Howell, A H
- Howell, A. Brazier (Alfred Brazier), 1886-
- Howell, Alfred B
- Howell, Arthur H
- Howell, Arthur H. (Arthur Holmes), 1872-1940
- Howell, Arthur M
- Howell, Benjamin F. (Benjamin Franklin), 1890-1976
- Howell, Brian E
- Howell, Buford Frederick.
- Howell, C D
- Howell, D L
- Howell, D. E. (Dariel Elza), 1910-
- Howell, D. V.
- Howell, Donna J
- Howell, Doug L
- Howell, Eric K
- Howell, Erik K.
- Howell, F Clark
- Howell, F. W.
- Howell, Fred G
- Howell, G J
- Howell, Gerard Charles Lisle.
- Howell, H. Spencer (Henry Spencer), 1857-1912
- Howell, Henry H.
- Howell, Hettie B.
- Howell, J A
- Howell, J F
- Howell, J Franklin
- Howell, J O
- Howell, J W
- Howell, J. M.
- Howell, Jacquelyn S
- Howell, John Fincher, 1926-
- Howell, John Thomas, 1903-1994
- Howell, John Warren
- Howell, Joseph C
- Howell, Joseph,
- Howell, Joseph, 1830-1912
- Howell, Joseph.
- Howell, K
- Howell, K M
- Howell, Kim M
- Howell, M J
- Howell, Mark D
- Howell, Meta P.
- Howell, Nathan
- Howell, Ruth M., 1889-1982
- Howell, S N G
- Howell, Spencer P
- Howell, Steve N G
- Howell, Terry A.
- Howell, Thomas J.
- Howell, Thomas R
- Howell, Thomas, 1842-1912
- Howell, W
- Howell, W M
- Howell, William H. (William Henry), 1860-1945
- Howell, William, Rev.
- Howells Water Garden,
- Howell's Water Garden.
- Howells, W. W. (William White), 1908-2005
- Howells, Y
- Howells, Yvonne
- Hower, A A
- Howerter, David W.
- Howerth, Ira W. (Ira Woods), 1860-
- Howery, M
- Howes, A. G.
- Howes, Alison
- Howes, Alton C.
- Howes, Brian Louis.
- Howes, C A
- Howes, F. N. (Frank Norman) 1901-1973
- Howes, G J
- Howes, George Bond, 1853-1905
- Howes, Gordon
- Howes, Gordon J
- Howes, Gordon Jon
- Howes, H. L. (Horace Leonard), 1882-
- Howes, J R
- Howes, Paul Griswold, 1892-
- Howes, Philip.
- Howes, William George 1879-1946
- Howes-Jones, Daryl, 1951-
- Howick, E. E.
- Howie, A
- Howie, A A
- Howie, T W
- Howie'S,
- Howison, George Holmes, 1834-1917
- Howitt, A
- Howitt, A W
- Howitt, Connor
- Howitt, Henry
- Howitt, J. E. (John Eaton), 1880-1966
- Howitt, Mary (Mary Botham), 1799-1888
- Howitt, Mary Botham, 1799-1888
- Howitt, Samuel, 1765?-1822
- Howitt, William, 1792-1879
- Howitz, D.
- Howkins, Heather F.
- Howland C. Bacon (Firm)
- Howland Nursery Company.
- Howland, A. F.
- Howland, Edward, 1832-1890
- Howland, Eliza W.
- Howland, George T.
- Howland, H R
- Howland, Henry R
- Howland, John Snowdon, 1885
- Howland, Joseph
- Howland, Joseph E.
- Howland, Keith H
- Howland, Llewellyn
- Howland, Ruth B
- Howland, Ruth B.
- Howlett, A
- Howlett, Bartholomew, 1767-1827
- Howlett, Derek
- Howlett, F M
- Howlett, Freeman Smith, 1900-1970
- Howlett, Joan S
- Howlett, Michael
- Howlett, Mike
- Howlett, R
- Howlett, W. L.
- Howley, B
- Howley, James P
- Howley, Rt
- Howley, T H
- Howorth, Henry H. Sir, (Henry Hoyle), 1842-1923
- Howorth, Sir Henry H
- Howorth, W.
- Howroyd, John
- Howse, H D
- Howse, Harold D
- Howse, M Thomas
- Howse, P E
- Howse, Richard
- Howse, Richard.
- Howse, Stafford C B
- Howson, C
- Howson, John S.
- Howth Demesne Gardens (Howth, Ireland)
- Howton, Harry Marshall.
- Hoxha, Tedi
- Hoxie, Jane Lincoln, 1863-
- Hoxie, Nellie H. M.,
- Hoxie, W J
- Hoy, B. (Benjamin), 1888-1966
- Hoy, C. C.
- Hoy, Dale
- Hoy, J A
- Hoy, J B
- Hoy, James
- Hoy, Joann M
- Hoy, Judy A.
- Hoy, M A