Are Your Herbaceous Perennials Sick?

Are Your Herbaceous Perennials Sick?

The Michigan Department of Agriculture and Rural Development (MDARD) has released a new survey that reports there is still a high incidence of imported virus-infected, bare-root herbaceous perennials in Michigan.

According to an article on the Michigan State University Extension (MSUE) website, many of the problems stem from product purchased through the USDA-APHIS Clearance Program. The USDA-APHIS website describes this clearance program as an initiative designed to enact procedures “designed to identify and/or mitigate the risk of exotic pest introductions through action taken in foreign countries.”


The study was conducted from 2006 to 2011 on hosta, iris, paeonia, dicentra and freesia plants that were shipped to several Michigan nurseries from various foreign countries. Over the testing period, the study results continually indicated that there were higher-than-acceptable virus rates on the plants. According to the study, “A comparison of virus tests performed in 2007, 2009 and 2011 indicates that the overall rate of virus infection in imported perennials has increased during this period.”

MSUE warns growers to be conscious of this problem and take preventative measures when growing these varieties. Visit the website for tips on identifying virus symptoms.

Click here to view the full report.

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Susan Martin says:

This article underscores the importance of purchasing bare root perennials through a reputable source. At Walters Gardens, which is the largest grower of bare root perennials in the nation, and is located in West Michigan, we test all of our stock for viruses annually and are extremely careful only to ship healthy, non-infected stock. Nearly all of our bare root perennials are grown here, not imported from other countries. Regardless of their source, all are tested for an extensive list of viruses before shipping out to any customers. One of the reasons our customers come to us for bare root perennials is because they know we are on top of the virus issue and have a 0% tolerance policy when it comes to plant viruses. Sadly, not all growers have this policy and give bare root perennials a bad name, as illustrated in your article. Hopefully, informed customers will know how to tell the difference between a reputable grower and one just looking to make a quick dollar on inferior quality product.