Viruses on imported herbaceous perennials

Recent MDARD survey results indicate some imported herbaceous perennials have high incidence of plant viruses. Be vigilant and recognize symptoms to protect against introducing new or unknown pathogens.

The Michigan Department of Agriculture and Rural Development released the results of a survey they did from 2006 to 2011 on imported herbaceous perennials looking specifically for viruses. The results show there are still problems with imported, virus-infected, bare-root, herbaceous perennial plants arriving in the state. This is an increasing concern for growers who purchase plants that arrive under the USDA-APHIS Preclearance Program. View the Survey for Viruses on Imported Perennials.

Herbaceous perennial growers need to recognize virus symptoms on their plants. In order to do that, I recommend you obtain a copy of the book Diseases of Herbaceous Perennials by Gleason, Daughtrey, Chase, Moorman and Mueller, published by APS Press. It contains great photos of symptoms and descriptions of the major pathogens by plant genus.

Another resource to identify viruses of herbaceous perennials is Gallery of Plant Virus Symptoms from the Wisconsin Department of Agriculture, Trade and Consumer Protection. This publication was also the result of funds from the Farm Bill like the MDARD survey effort.

If you suspect plants have a virus, contact your Michigan State University Extension nursery educator for further assistance, or send samples directly to MSU Diagnostic Services.