Plant Import Regulations
Quarantine 37
Intentional horticultural and nursery imports are the top pathway for the introduction of invasive plants that threaten biological diversity. Purple loosestrife, Scotch broom, Japanese and bush honeysuckles, English ivy, Dalmation and common toadflax, butterfly bush, and Russian olive are just a few examples of garden plants that have escaped, spread, and replaced native species while often costing taxpayers millions of dollars to control or changing ecosystem function in natural areas.
Our nation’s trees are also under attack by pests that have likely been imported with plants. These range from sudden oak death and the glassy-winged sharpshooter (an insect) in California to cactus moths, beech scale, and the fungus steadily killing dogwoods, all in the East.
Through the Animal and Plant Health Inspection Service (APHIS) the U.S. Department of Agriculture (USDA) has the authority to regulate imports of horticultural and nursery plants. These regulations, known as Quarantine 37, apply to plants or parts of plants intended for cultivation, planting, or propagation. APHIS has used these rules to block import of the devastating pests and diseases—mostly those of agriculture—that can hitchhike on imported plants. Quarantine 37 has never been applied to plants, themselves, as potential pests.
The USDA has joined its critics in acknowledging that current Quarantine 37 rules are no match for:
- massive and steadily increasing volumes of plant imports, now about 500 million plants per year;
- the taxonomic diversity of the plants being imported and their multiple points of origin;
- the high rate at which pests are being intercepted by federal plant inspectors at borders – in the thousands per year – and the possible saturation of the inspection system;
- the high disease and pest risk of plant materials intended to be immediately distributed and planted; and
- advances in the science of biological invasions, especially understanding of their economic, environmental, and health impacts, as well as now-established ways of assessing and predicting risk.
In fact, regulations governing imports of “plants for planting” (as the USDA terms them) are substantially weaker than those for importing fruits and vegetables, even though the latter are imported in smaller volumes, are inspected more frequently, and pose fewer financial and environmental risks than horticultural imports.
The USDA began preparing the first major changes to Quarantine 37 before 2004. These first proposed regulatory changes would create a special category of plant imports that could not be imported until their risks were assessed—and deemed acceptable.
The success of risk-screening programs in other countries, as well as numerous scientific studies, show that both experts and policy makers can make practical and reliable decisions on which plants to exclude from import. Risk-screening based on factors such as the plant species’ invasiveness elsewhere in the world; the likelihood and amount of plant material to enter the country; the match between habitats and climate in the United States and other countries; the difficulty of control, should it become invasive; and its potential for economic and ecological damage can all be used objectively to determine if a plant should be imported.
Such risk determinations, or “screening,” for plants is the subject of APHIS’s first proposed change to Quarantine 37. The proposed rule goes by the name of “not allowed for importation pending pest risk analysis” or NAPPRA. This is a key change. It is critical that new USDA Secretary Tom Vilsack make its implementation and further, strong changes to Quarantine 37 a top priority.
