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Late Freezes

A late freeze like the one that we’ve had here are damaging to agriculture in more ways than you’d expect. Some of the effects won’t be seen for several months. I think as humans we always want to know what’s coming next. We can’t know anything for certain. That is something we’ve all learned over the last couple of months. However, the weather conditions that we’ve had can give us some clues on what might happen.

The main part of the plant that is impacted is the flower. If the flower on a plant dies prematurely, then that plant won’t produce any fruit or seed. Locally, many of the apple growers have been hit by the late frosts. The vineyards have also had a hard time dealing with the late frost. In some orchards and vineyards, growers will place fires around to try to keep plants just above freezing temperatures. It takes a lot of work to keep those fires going through the coldest part of the night. Some vineyards have giant wind machines that mix the air from high and low lying areas to try to raise the temperature.

Annual plants can also be bit by freezes. Perennials are more hardy and able to withstand a freeze. Scientists believe a plant’s ability to withstand a freeze has to do with the fats that make up the cell membrane. Usually it takes a week or so before you see freeze damage. Covering annuals with a bucket or sheet traps the heat that is radiated from the earth at night, creating a miniature greenhouse.

Seed germination rates will also decline with a freeze. Cold temperatures allow seedling diseases to get in and attack a seed. Low soil temperatures also slow down germination. Generally speaking, seeds need soil to be at least 65 degrees to be able to germinate.

Acorn production is also negatively impacted by a late freeze. Oak trees will have male and female flowers on the same tree. The technical term for this is monecious. Oak flowers are very small, and are wind pollinated. Generally speaking oaks can be broke down into white oaks and red oaks. A red oak’s acorns take 15 months to mature. Therefore, in years with a late freeze, red oaks will still produce a crop. White oaks can be froze out by a late freeze.

Why does acorn production matter? Many species of wildlife rely heavily on acorns for food. Pigeons, ducks, woodpeckers, bears, deer, and hogs all eat acorns. Throughout the summer, there is enough forage for wildlife to eat, but as fall and winter arrive, they need acorns for their diet. If there aren’t enough acorns to go around, they will come looking for food. With smaller animals, this isn’t very problematic. However, with bears, deer, and especially hogs they can do damage. Hogs in particular can be very damaging to property including lawns, pastures, and anything else they can get their tusks into. Hogs cause $1.5 billion in damage every year in the US.

If you have questions about freeze damage contact your County Extension Office or email me at .