National Plant Board

Plant Quarantine, Nursery Inspection, and Certification Guidelines

Appendix M

Good Nursery Practices

Nursery and greenhouse production practices generally are not regulated. Exceptions include practices which must be followed in order to meet quarantine or plant registration and certification program requirements. Nonetheless, production practices in all phases of growing and marketing nursery and greenhouse plants–from propagation through sales and delivery–may influence whether those plants consistently meet nursery stock pest freedom standards or quarantine requirements.

The following are general guidelines that regulatory officials should encourage growers to follow to produce nursery stock that will meet or exceed federal and state nursery stock pest freedom and quarantine requirements. State needs and growing conditions vary considerably. Therefore, each state may want to develop guidelines that will address specific local needs and conditions. Regulatory agencies might be able to employ their cooperative extension service specialists to develop appropriate guidelines. The agency could then reproduce and distribute them to each nursery operator as a means of helping to assure compliance with pest freedom requirements.

Plant propagation – use sterile media whenever possible; use clean pots or trays; use pest free plant sources of propagative stock.

Pest management – become knowledgeable about local insects and diseases that may affect plants in the nursery, and appropriate management or control measures with emphasis on cultural practices when possible; establish an regular scouting program, and establish pest population thresholds to trigger control measures; maintain pest monitoring records, and pesticide application records, as may be required by federal and/or state law.

Weed control – control weeds, as many are pests and others can harbor insects and diseases.

Soil fertility – maintain appropriate soil or media pH and nutrient levels; test for soluble salts, nutrient levels, etc.; identify symptoms associated with macro and micronutrient deficiencies and high soluble salts.

Water management – routinely test water supply for proper pH, filter and treat as needed to control pathogens and eliminate weed seed.

Plant spacing – allow enough space for proper growth and good air circulation to help prevent favorable disease conditions.

Removal of plants – rogue-out and dispose of injured, dead or dying plants, as they can harbor insects and diseases. Good sanitation in all aspects of production is important.

Know your sources – buy plants, media, fertilizers and other supplies from known, reputable suppliers; be sure sources for plants ar properly licensed and certified to ship into your area; keep records of all plant sources and shipments received. Isolate and inspect plant shipments on arrival; eliminate any pests discovered before introducing into nursery operation.

Know your markets – keep aware of federal and state shipping and quarantine requirements for all areas to which nursery stock is shipped and maintain records of shipments and any compliance information.