Why Richters Can't Ship Oregon Grape to the U.S.

My name is Alicia Hill-Force, and I am in Washington State. I was looking over your catalogue, and I had a quick question for you. I noticed that you will not ship Oregon Grape to the States. Is there an environmental reason for that? Thanks for the info.

There a few plants and seeds that Richters cannot ship to the United States. For most of these the reason is they are prohibited from importation by the U.S. Department of Agriculture (USDA).
Usually importation bans are imposed because the prohibited plant acts as a host for diseases that could attack other commercially important plants. For other plants or seeds, it is because the plant itself is considered a threat as an invasive plant. Bans on invasive plants can be imposed by the USDA, or by the state and municipal governments.
In the case of oregon grape (Mahonia aquifolia), the USDA has banned importation of plants into the U.S. because it is a disease host.