Commercial Horticulture

Plants growing in Fischer Greenhouse

The University of Delaware Cooperative Extension Commercial Horticulture Program provides non-biased, research based information for growers, retailers, greenhouse operators, landscape contractors, landscape maintenance professionals and other green industry professionals in Delaware, the region, and the nation.  Horticulture is the science, art, technology and business involved in intensive plant cultivation for human use.  It includes non-food crops such as flowers, trees, shrubs, lawns, etc. and food crops (fruits, vegetables, mushrooms and culinary herbs), which are covered in the UD Vegetable and Small Fruits Program.

The needs of the green industry are addressed with applied research and demonstration projects focusing on sustainable landscape installation and management as well as pest control.  The information and knowledge is disseminated through a range of venues in collaboration with the Delaware Nursery and Landscape Association (DNLA), including educational meetings, short courses, tours, publications, newsletters, direct contact and this website.

A certified nursery professional program is administered through the DNLA to help industry professionals learn technical information and demonstrate their professional standing.

2024 UD Cooperative Extension Horticulture Short Courses

Register now, pay later.  Registration fees will be collected at each short course for which you have registered.  Cash or check made payable to University of Delaware.  The registration fee for each short course is $20.00 unless otherwise noted. 


Pest and Beneficial Insect Walk, Carvel Center


June 20, 4–6 p.m., 1 CNP, 2 Pest., 2 ISA credits

Sussex County Extension Office, 16483 County Seat Highway, Georgetown, DE.

Learn to identify insect and disease pests, as well as beneficial insects in the landscape at the Sussex County Extension Office. Find out what signs and symptoms are used to identify pests and diseases.

Instructors: Jill Pollok, Brian Kunkel, and Tracy Wootten


Hands-On Disease and Insect ID Workshop, College of Agriculture and Natural Resources Campus


Wednesday, July 10, 4 – 6 PM, 1 CNP, 2 pest., 2 ISA credits

College of Agriculture and Natural Resources, Room 012 Townsend Hall, 531 S College Avenue, Newark, DE.

Learn what signs and symptoms the Extension Specialists use to identify pests and diseases! Tips and techniques will be shared. Fresh and preserved specimens will be available to look at using hand lenses and microscopes. 

Instructors:  Jill Pollok, Brian Kunkel, and Carrie Murphy

Hands-On Disease and Insect ID Workshop, Carvel Center


July 11, 4 – 6 PM, 1 CNP, 2 pest., 2 ISA credits

Sussex County Extension Office, 16483 County Seat Highway, Georgetown, DE.

Learn what signs and symptoms the Extension Specialists use to identify pests and diseases! Tips and techniques will be shared. Fresh and preserved specimens will be available to look at using hand lenses and microscopes.  

Instructors:  Jill Pollok, Brian Kunkel, and Tracy Wooten

Register Online

Or, check the workshop description for the meeting location and register by contacting your County Agent:

Carrie Murphy, New Castle County Short Courses (302) 831-1426 or

Tracy Wootten, Sussex County Short Courses (302) 856-7303 or

Plant of the Year

  • Plant of the Year - Each year the Delaware Nursery and Landscape Association selects a woody and herbaceous plant that thrives in Delaware and should receive more attention in the trade.  Plants are suggested by a team of loca professionals and the DNLA board votes on the winners.  A one-page colorful flyer is developed to promote the winners each year.

Native Plant Nurseries serving Delaware and the region


The Greenhouse and Nursery industry thrives on the Eastern Shore.  Delaware has several large greenhouse operations and nurseries.  There are also major nurseries in our neighboring state of Maryland.  The Green Industry Consortium is a national group of horticulturists and Ag Economists who have been addressing the needs of the Green Industry for over 25 years.  The Green Industry Consortium has developed many publications for this industry.  The Greenhouse publication is for start-up or existing greenhouses and was part authored in Delaware.  The Specialty crops initiative has provided funding for a number of specialty crops projects in the United States.  A project conducted in Delaware to help nurseries explore growing more native species is listed below.

Delaware Livable Lawns

The Livable Lawns Program certifies lawn care companies that follow environmentally-friendly practices in fertilizer application while educating property owners.

Water Quality Research

  • Winterthur/Applecross -This multidisciplinary project research site is located at Winterthur Museum and Gardens, where the team will compare the quality of a stream impacted by traditional mowed landscapes versus another stream that only receives runoff from meadows, forests and landscape beds. One of the primary goals of the project is to curb water pollution at its source — preventing pollution in the first place rather than waiting to treat contaminated water after it enters waterways.

Green Industry Training at your Site


Delaware Cooperative Extension will work with you to conduct a workshop at your site, for your employees.  A menu of available topics is included below. 

For a one-hour talk from the prepared menu, the cost will be $300 for a minimum of 10 people.  If you have more than 10 people, it will be an additional $5/person.  For talks that exceed one hour and/or include nutrient management or pesticide credits, there will be an additional cost determined by the County Agent.

Scheduling is based on the availability of the instructor with expertise in the topic you choose. You will need to provide a meeting space to accommodate attendees. Please schedule early to have the best chance of getting the extension professional with the appropriate expertise on your chosen topic in a timely manner. 

Available topics:

  • turf management/maintenance

  • integrated pest management

  • insect identification and management

  • weed identification and management

  • disease identification and management

  • plant diagnostics with microscopy

  • abiotic and cultural plant problems

  • soil basics - chemical and physical properties

  • sustainable landscapes

  • backyard wildlife habitat

  • basic vegetable production

  • soil testing for turfgrass systems

  • pesticide safety and handling                                     

  • fertilizer management 

  • general mathematics for pesticides/fertilizers

  • spreader/sprayer calibration                                       

  • understanding pesticide labels

  • post-construction stormwater management               

  • water quality in stormwater ponds

  • invasive plant management    

Our team is willing to work with you to offer any other nursery or landscape industry topic for which we have expertise, and that interests you and your employees.  Please discuss with your County Agent.

Please contact your County Agent for additional details and to schedule:

Carrie Murphy, Horticulture Agent, New Castle County:  (302) 831-2506 or

Blake Moore, Renewable Resources Agent, Kent County:  (302) 730-4000 or

Tracy Wootten, Horticulture Agent, Sussex County:  (302) 856-7303 or


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