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William H. Darr School of Agriculture

Pamela Borden Trewatha, Ph.D.

Professor Emeritus, Horticulture and Plant Science

Room 226 Karls Hall


New weeds, information being added to Midwest Weed ID link above during fall 2015-- follow link for more information.

I am now retired, but still enjoy assisting in weed and other plant identification.  Please e-mail photos of any unknown plants/weeds to me at the address above, and I will respond as soon as possible.

E-mail is also the best way to contact me now for other inquiries.

Educational Background:

  • B.S. in Plant Protection, 1978, Purdue University, Department of Botany & Plant Pathology
  • M.S. in Horticulture, 1982, Kansas State University, Department of Horticulture
    • Emphasis on woody ornamental production; research on use of growth retardants on container-grown blue holly
  • Ph.D. in Horticulture, 1987, Kansas State University, Department of Horticulture
    • Emphasis on turfgrass physiology; research on enhancing spread and reducing water use of zoysiagrass cultivars by use of growth regulators       

Research Interests: (although retired, I'm still working on several research activities)

  • I'm currently working on writing a midwest weed identification manual and am continually researching and photographing weeds throughout the midwest
  • Surveys of new weed species spread in Missouri and throughout midwest
  • Native plant production, restoration and adaptation for use in ornamental horticulture
    • production and evaluation of prairie/dryland wildflowers for sustainable landscapes
    • evaluation of western native oak species for use in Missouri
    • root system development in oak seedlings to identify native oaks for successful inclusion in nursery/landscape industry
    • evaluation of spruce species for use in Missouri
  • Past research has included evaluation of native warm-season grasses for allelopathy, effect of herbicides on native warm-season grass mycorrhizae, turfgrass cultivar evaluation trials