Virus Testing for Your Garden 2020

As a result of restrictions on the WSU laboratory working conditions mandated in response to the Corona virus, the number of participants in the project will be substantially reduced.  Check with Ron Miner at to see if testing opportunities are still available.

Yellow veins indicate virus

With the cooperation of Professor Pappu at Washington State University (WSU) and the support of the Scheetz-Chuey Foundation, the Clean Dahlia Center at WSU will test our dahlias for virus again this year.

The testing project follows from two key observations.  First, dahlias that are tested and found to be free of virus produce tubers and plants in the subsequent year that have a significantly lower incidence of virus than untested plants.  Second, dahlias that test positive for virus produce tubers and plants in the subsequent year that virtually always have virus! 

There are three critical steps required to reduce the presence of viruses in our gardens.  The first is to acquire clean stock whenever possible.  The projects listed here target making clean stock more readily available.  Second is to remove plants with virus from your garden.  The testing projects listed here can help to do that in a rigorous way.  An effective alternative is to remove and destroy plants with suspicious foliage (usually yellowing veins).  “If in doubt, throw it out.”  Third, avoid transferring virus from plantings with virus to clean plants by disinfecting your cutters, in particular.    Procedures for disinfecting your tools are available in the “Understanding Virus in Dahlia” page on this website


Free Testing for Vendors

A large number of test slots have been reserved for dahlia vendors who choose to take advantage of a free and confidential testing program.  With the support of the Scheetz-Chuey Foundation, the ADS will cover the costs of the authorized tests.  Applications for participation in the program will be accepted until June 30.  The application instructions are available here.

If you applied for the program and received confirmation of your participation, please follow the instructions  here  for submitting your samples.


Subsidized Tests for ADS Societies

The objective of this project is to increase the availability of clean stock within ADS Participating and Affiliated Societies across the USA.  (We are working on a different approach for testing samples from our Canadian ADS Societies.)  The clean plants that are identified can provide the tubers that will serve as the source for propagating clean plants for 2021 and subsequent club sales.  With the support of the Scheetz-Chuey Foundation, the ADS will cover half ($150) the cost of testing the basic set of 30 samples for each ADS society.  It is our experience in the Midwest Conference Spring Auction that plants grown from clean stock command a substantial premium.  The costs for the testing were readily recovered in the sales of those special plants.

It is also our experience that the first tests yielded more virus than expected.  Participating societies should anticipate that it could take several years to achieve a high percentage of clean plants.  Up to 60 additional samples can be submitted at a cost of $10 per sample.

The key first step for your society to identify a project coordinator.  That chairman should apply for the program as soon as possible but no later than July 31.  Application instructions are available here .

A schedule for sending samples will be supplied to the club representative for the program.  The instructions and the forms for sending the samples are available below.


Open Testing

The program for the testing of sets of 30 or more samples for $10 per sample is available again this year.

Please follow the instructions available here for submitting your samples.


Turn-Around Time for Results

We anticipate that the turnaround time to receive the test results will be approximately one month.  Be aware, however, that the time will depend on the number of samples submitted. 

In any case, you should be prepared to store tubers from test plants before you know the virus results.  That will require careful tracking of the tubers from the test plants in storage.

Professor Pappu and his group at WSU and in the Dahlia Resource Center will run the (sophisticated!) tests as quickly as possible.  However, accuracy will continue to be more important than speed in generating the test data.


Links for Applications, Instructions, and Submission Forms


Application for Participation pdf
Instructions  pdf
Submission Form docx or pdf
Sample Tags docx or pdf

ADS Participating and Affiliated Societies:

Application for Participation pdf
Instructions pdf
Submission Form docx or pdf
Sample Tags  docx or pdf

Open Submissions:

Instructions  pdf
Submission Form  docx or pdf
Sample Tags  docx or pdf