Ice, ice baby: How to prevent your plant diagnostic samples from freezing

Heidi Wollaeger<wollaege@msu.edu>, Michigan State University Extension - March 03, 2015

Insulate your plant samples before shipping them to the MSU Diagnostic Services lab to prevent freezing.

We recommend you ship your plant sample in a plastic foam cooler when the outdoor air temperature is below freezing. Photo credit: Jan Byrne, MSU Diagnostic Services

February 2015 was the coldest February on record in many locations in the Midwest. According to weather data recorded at the Traverse City Enviro-weather station, the air temperature fell below zero degrees Fahrenheit on 12 days in February and was its lowest on Feb. 20 at -16 F. At the Commerce Township Enviro-weather station in southeast Michigan, temperatures dipped below zero 16 different days with a low of -25 F. With the presence of this artic air, growers shipping plant samples to Michigan State University's Diagnostic Services should provide the plants with extra insulation to prevent them from freezing.

Recently, MSU Diagnostic Services has received numerous plant samples that have arrived frozen. Once the plants have been frozen, the lab cannot use the sample to identify pest, nutritional or pathogen problems. So how can you prevent wasting your money by shipping a plant that arrives frozen?

Michigan State University Extension recommends hand-delivering the plant sample, if possible, while temperatures are below freezing. If you choose to still ship your sample, we recommend that you provide adequate thermal insulation. You will need to heavily wrap your plant sample in bubble wrap or place it in a plastic foam cooler, such as Styrofoam, which provides the most protection from the cold.

Furthermore, we recommend shipping your plants to MSU Diagnostic Services through FedEx or UPS instead of the U.S. Postal Service. Packages shipped through FedEx and UPS arrive directly to the door of the diagnostic lab, minimizing the time in shipment. Packages shipped through the U.S. Postal Service must first be sorted at the University Stores. Ship your plants with same day or overnight delivery. Also, never ship plants to the diagnostics lab on a Friday.

For other tips on how to send samples into the MSU Diagnostics Lab, visit the MSU Diagnostic Services website.

This article was published by Michigan State University Extension. For more information, visit https://extension.msu.edu. To have a digest of information delivered straight to your email inbox, visit https://extension.msu.edu/newsletters. To contact an expert in your area, visit https://extension.msu.edu/experts, or call 888-MSUE4MI (888-678-3464).