The month of March is concluding; and it was a wild one at that. Global warming, or more accurately ‘global weirding’, is not only evident but now fully apparent after a winter with record low snowfall and unusually high temperatures. Earlier this month there were two weeks of unseasonably warm 70 and 80 degree weather, yes 80 degrees in March. The common folk may relish in this warmth, but any gardener, farmer, or orchardist
understands the multitude of implications. One night last week the temps dipped down into the high twenties. Whats wrong with that, those are usual March conditions, right? Well yes, but remember that two week period of 70 and 80 degree temps? Those warm days triggered local flora to ‘go for it’…inducing extremely early blossoming and bud break on many trees. Some of these trees being cornerstones for local economies. Stone fruits(peaches,plums,cherries,etc.) were particularly premature in blooming. Their blossoms are very tender and cannot withstand frost. There you have it, confused trees put out flowers and then got zapped by the cold. The cherry industry in the Traverse Bay area took a hard blow; a friend reports that the entire crop for 2012 could be in the red…except not with plump, juicy cherries! Another reason not to put all your eggs in one basket. The only potential saving grace for these cherry farmers is the fact that the high winds associated with the cold temps inhibit frost from settling. Conventional farmers combat this with giant fans or ‘smudge pots’ (oil burning devices used to increase air temps ever so slightly) throughout the orchard. However, for most small farmers this is too costly and labor intensive. On a home scale it is much easier to protect plants from frost. Simply draping a tarp or blanket atop vulnerable specimens will help to prevent frost contact. The hardy kiwi vines in my garden did not appreciate the frost. They didn’t have flowers but they had leaves. Key word ‘had’. Even with protection the leafed-out hardy kiwi vines could not take the cold temps. Fortunately they will happily leaf out again when the conditions become favorable. Fingers are crossed that the apples will be okay. Some varieties are at
the tight cluster or pink stage which means flowers could open up any day. We’re not in the clear yet. A year with no cyder would be a shame indeed, but who knows maybe it will be just as bountiful a season as last for apples. Another factor that influences successful fruit set is the presence of pollinators. Under cold temps most pollinator species haven’t become fully active yet. Even wild edibles like stinging nettle and cattail are way ahead of their normal growth cycle. Fortunately there isn’t nearly the risk with these guys. The wise gardener knows not to put out tomato seedlings because one week of 70 degree temps in March. This would be foolish. However, I did take a risk by direct seeding some bush beans in my greenhouse during the warm spell. Hopefully they’ll be okay. Not much to lose there, though.
So you get the picture— everything is at least a month ahead. This is not just in MI either; New York, Ohio, Indiana, and several other states are experiencing similar weather abnormalities. The rest of the season remains more unpredictable than ever. One thing that is certain, though, is that adaptability will be key to having a resilient food system under such adverse climatic conditions. When selecting fruit tree varieties it may be wise to choose cultivars with an array of different chilling hours, even in the north we may need to
consider low chill varieties at the current rate. Or, perhaps an opportunity exists to ‘push the zone’ by growing figs and Asian persimmons in MI. The most recent USDA Plant Hardiness Map already reveals the shifting of zones. The Asian persimmon cultivar ‘Izu’ has lived for two seasons now in my unheated hoophouse. Maybe one day it’ll reach fruition! These are ideas worthy of consideration, but don’t get overzealous and start planting citrus in your yard. I would love to hear other people’s experiences so far this season. Hopefully the weather hasn’t wreaked too much havoc on your plantings!