Winter injury was assessed in March 2018, using the "bud chop method". Popular cultivars and advanced breeding materials were tested. The weather data for a nearby weather station to the Horticultural Research center (Chaska WFSO) are presented in Figure 1. We use the cli-mate website  to download the data for our site. This is an easy to navigate website that provides daily, monthly, and seasonal reports.

Figure 1. Weather station data for Chaska, MN from October 26, 2017 through March 15, 2018.

Bud survival was caculated from 48 compoun buds of each variety. Percentages are shown for the 2018 primary and secondary bud survival. Also shown in Table 1 is the average bud survival for years 2013-2018, and also the average for the same years with out the 2014 Polar Vortex data.

Table 1. Primary and secondary bud survival data for cold hardy varieties and breeding lines for the 2017-18 winter. Averages for 2013-2018 and 2013-2018 without 2014 data.