NC State Extension


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 disinfesting 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:

Boxwood Blight Research:

Commercial Nursery Information:

Christmas, Forest, and Landscape Tree Information:

Floriculture Information:

Landscape Information:

Nursery Crops Information:

Questions regarding disease problems in commercial floriculture, nursery crops and Christmas trees should be directed to the Plant Disease and Insect Clinic, NC State University:

Disease Factsheets

Phytophthora root rot on Fraser fir     NCSU Factsheet

Rose diseases and their control in the home garden     NCSU Factsheet

Powdery mildew of ornamentals and shade trees     NCSU Factsheet

Nematodes and their control in woody ornamentals in the nursery     NCSU Factsheet

Nematodes and their control in woody ornamentals in the landscape     NCSU Factsheet

Pine wood nematode     NCSU Factsheet

Holly diseases and their control in the landscape     NCSU Factsheet

Slime flux/wet wood     NCSU Factsheet

Southern bacterial wilt on marigolds     NCSU Factsheet

Scorch diseases on shade trees     NCSU Factsheet

Entomosporium leaf spot on red tip     NCSU Factsheet

Rhododendron diseases     NCSU Factsheet

Phytophthora root rot and its control on woody ornamentals     NCSU Factsheet

Damping-off in flower and vegetable seedlings     NCSU Factsheet

Juniper diseases and their control in the landscape     NCSU Factsheet

Azalea diseases and their control     NCSU Factsheet

Diseases of Leyland Cypress     NCSU Factsheet

Dutch elm disease     NCSU Factsheet

Common pine diseases and their control     NCSU Factsheet

Common diseases of gold-dust plant     NCSU Factsheet

Dogwood diseases     NCSU Factsheet

Root and butt rot of oaks     NCSU Factsheet

Nematode management in bedding plants     NCSU Factsheet

Phytophthora blight and root rot on annuals and herbaceous perennials     NCSU Factsheet

Sanitizers recommended for ornamental plant production     NCSU Factsheet

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