Ornamental crops, which include floriculture and nursery products, have been the fastest growing agricultural sector in North Carolina over the last decade. However, nurseries and greenhouses are not isolated geographically, and the movement of both propagation and finished stock occurs across the globe. Due to this movement of plant material, North Carolina is faced with the constant threat regarding the introduction of exotic or regulated pathogens into our state on infested plant material or in potting substrates.
The foundation of all disease management programs in commercial floriculture and nursery crops is integrated pest management, better known as IPM. For ornamentals, IPM starts with good sanitation practices that eradicate and prevent movement of pathogen inoculum in the crop production system. Inspecting buy-ins for symptoms of plant disease is a key step in an established IPM program. Maintaining stock plants for propagation that are pathogen-free ensures the perfect start to an IPM plan. Removing crop debris after sales and disinfecting surfaces in production areas are two examples of sanitation in practice. Sanitation is one of the most critical steps in IPM because it eliminates pathogen inoculum. Cultural practices that avoid moving plant pathogens through the production system, such as treatment of irrigation water, is another good IPM practice. Avoiding the re-use of untreated propagation trays, flats, and pots that are proven carriers of pathogens like Rhizoctonia, Phytophthora, and Thielaviopsis from previous crops can eliminate sources of pathogen inoculum. Some plant viruses are systemic in their host so any hand planting, trimming, or just picking up a plant to move it can result in the worker or tool moving the virus to a healthy crop. Finally, many fungal and bacterial plant diseases can be prevented in ornamental crops by following good IPM practices and combining them with the use of preventative fungicide and bactericide applications. Many products are commercially available; please refer to the Ornamental Chemical Control for NC below.Boxwood Blight Management:
- Prevention and Management of Box Blight
- Video on Fungicides for Management of Box Blight
- Most Effective Fungicides for Preventing Box Blight
- Box Blight Fungicide Results - 2012
- Box Blight Fungicide Results - 2013
- Best Box Blight Fungicides from 2012-2013 trials
- Boxwood Cultivars with Tolerance to Box Blight - 2013
- Boxwood Cultivars with Tolerance to Box Blight - 2012
Boxwood Blight Research:
Commercial Nursery Information:
- Disease control: Nurseries and Landscape
- Relative Effectiveness of Fungicides in Woody Ornamentals
- Sudden Oak Death in Nurseries
- Managing Storm and Disaster Damage in Landscapes and Nurseries
- Disease Control: Nursery Crops
- List of Sanitizers for Tools, Surfaces, and Equipment Sanitizers
- Efficacy of Products for Disease Control in Annual, Bedding, and Flowering Potted Plants in Greenhouses, Nurseries, and Landscapes
Christmas, Forest, and Landscape Tree Information:
- Disease control: Christmas, Forest, and Landscape Trees
- Management of Phytophthora root rot on Fraser Fir
Floriculture Information:
- Disease Control: Floriculture Crops (NC Agricultural Chemicals Manual)
- 2025 Guide to Ornamental Fungicides (printable)
- Prevention and management of soilborne diseases or ornamental plants and vegetables in the greenhouse
Landscape Information:
- List of Phytophthora Tolerant Hosts for the Landscape
- Sudden Oak Death in Landscape
- 2025 Guide to Ornamental Fungicides (printable)
- Management of Root-knot Nematodes in Bedding Plants
Disease Factsheets
- Damping-off in flower and vegetable seedlings
- Phytophthora blight and root rot on annuals and herbaceous perennials
- Bacterial leaf spot on greenhouse ornamentals
- Black root rot on ornamental plants
- Botrytis blight on greenhouse ornamentals