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Ornamental Plants

The Department of Horticulture and Landscape Architecture is committed to supporting the people and industries of Oklahoma through targeted ornamental plant research and educational programs.

Ornamental Selected Research

Plant Trials

Garden Debut® is a Superior Landscape Collection made up of Great New Plants™ and Trusted Selections™ that have been thoroughly tested for long-term performance through Greenleaf Nursery. The Proven Winners™ brand was founded in 1992 with the goal of introducing the best, most unique, high performing plants, to produce them under the highest quality standards, and to market the plants innovatively.  Plants from both trials are available from garden centers or independent retailers throughout North America. Both trials are located at the Botanic Garden at Oklahoma State University in Stillwater, OK. These gardens have areas for the general public to become acquainted with plants that grow well in Oklahoma.


Proven Winners research


Plant Growth Regulators (PGRs)

Greenhouse grower are constantly trying to control plant quality with the use of chemical plant growth regulators.  Most are used for controlling plant height, but some can be used to increase branching, which can save on labor costs while producing a better quality plant.  Poinsettias has been a staple for the Christmas holiday for almost a century and are the #2 potted crop in terms of value.  Although the genetics have improved, all varieties need to be pinched to encourage lateral bud growth.  however, some varieties do not branch consistently to produce a marketable potted crop. Current research is looking at using Attrimmec to increase branching and plant quality in poinsettias.

Colored Shade Netting

Research will evaluate colored shade cloth for cut flower production to compare yield and quality to support local market production.  To control heat during the summertime, growers use black shade netting to cool the greenhouse.  Knowing that plants respond to specific wavelengths, colored shade netting technology has begun to emerge but is not widely tested in the U.S. despite other countries reporting longer stems, improved yield, and more compact plants depending on the species and shade netting color used. This research will evaluate two different species response to three different colored shade nettings.  Data will be collected on plant growth to make a recommendation on the value of adapting an already common method used in production of the crops.

Potted Plant Production is a Billion Dollar Market in the Plant Industry

Growers are looking for ways to increase production quality while decreasing cost and environmental impact. The use of nondestructive, optical sensors has been investigated on twelve different greenhouse crops (including poinsettia, chrysanthemum, marigold, and geranium) to improve nitrogen use efficiency, increase plant quality, develop a sampling protocol, and reduce costs associated with other sampling methods.

Fact Sheet HLA-6719 has been developed to inform growers about optical sensors. Results from the studies have shown that for all but one crop, the atLEAF chlorophyll sensor performed as well as the SPAD chlorophyll meter, which is considered the standard but costs ten times as much as the atLEAF sensor. Location of sensor readings within a leaf and not just location within a plant canopy can affect readings.  In addition, a new mobile iPhone app (Plant Nitrogen Recommendations) was developed where someone can input atLEAF, SPAD, or leaf nitrogen lab analysis values into the app for over 150 different ornamental crops. The app then gives a recommendation if additional fertilizer is needed.  Current research is looking at how many samples are needed for accurate analysis, what affect other nutrients have on sensor readings, and how timing of fertilizer application can affect sensor readings.

Contact Information

Contact Information

We invite you to learn more about our department and the many opportunities available to you. If you have any questions, feel free to contact us.

David Hillock, State Master Gardener Coordinator
David Hillock
Assistant Extension Specialist
Consumer Horticulture
358 Agricultural Hall

Mike Schnelle, Shackelford Endowed Professor of Floriculture, Oklahoma State University

Mike Schnelle
Shackelford Endowed Professor of Floriculture
Commercial Horticulture
358 Agricultural Hall

Bruce Dunn
Associate Professor
Departmental Greenhouses, Coordinator
358 Agricultural Hall