As temperatures recently settled into the upper twenties and a heavy spring snow descended on the area, Jeff Burbrink, Elkhart County Purdue Extension guru, sent out an excellent resource. I reported in a Facebook Live video the cold damage at Wellfield (as of posting time) was pretty minimal. In truth, it can take days or weeks sometimes to assess the full effect of cold damage.
I learned something new from the extension publication I thought I would highlight: checking flower buds for cold damage. The further along a flower bud is developmentally affects its tolerance to spring freezes, and different species respond differently. Sacrificing a few flower buds is the best means of determining the extent of cold damage to fruit crops. The flower bud might still flower out (a good thing for ornamentals) if the petal tissue is not affected, however it is the flower receptacle tissue to be concerned about when it comes to fruit setting. All you need is a sharp razor blade, knife, scissors or finger nail to examine the bud. Slice the bud opens lengthwise, as several excellent Purdue videos demonstrate, and look for dark brown or black tissue. If there is any dark discoloration, regardless of the amount of green, the bud will not lead to fruit. Thankfully, as I stated on Facebook, the gradual cool down, taking several days to reach dangerous low temperatures, slowed many plants down enough to prevent worse damage. The most dangerous conditions occur with relatively warm sunny days followed by quick, dramatic swings to the freezer. Plant tissues, in these instances, do not have adequate time to adapt and build some tolerance. Rather, they are caught with their bud scales down, a situation that is decidedly not cool.
Josh Steffen, Horticulture and Facilities Manager