Yesterday morning, our lettuce and spinach was coated in frost, the leaves stiff. The roses down the street were stiff and cracked when I touched them. Fall has ended and, from a plant’s standpoint, winter has begun.
On the nights of November 12-13 and November 14-15 2012, the temperature dipped below 28F at about 3am and stayed below 28 for over four hours. This qualifies as a killing frost – a temperature low enough to kill sensitive plants. Trees, shrubs and native grasses are already dormant and not harmed by these temperatures. Sensitive garden plants, vegetables, anything in flower and flowers on some fruit trees were extinguished, although it looks as if some roses have survived. All the leaves fell off my pawpaw trees overnight.
Growing seasons are definitely getting longer. For Fayette County, Kentucky, this years frost-free season lasted from March 6 to November 13, a total of 252 days. The record growing seasons were 2009 and 2011, both at 261 days. Note that these numbers are for killing frost, 28F, not light frost, 36F. I will be doing more analysis of growing season length in a later post.
Longer growing seasons have economic consequences. Farmers can plant earlier, and fall vegetable crops are on the market longer. However, many plants, especially fruit trees, get tricked. One of my pear trees flowered in October and is bearing fruit in November. Of course, this fruit will not mature. Unfortunately, this tree will bear no fruit next year, because the flowers that developed in October were the ones that would have developed next year.
This butterfly was sitting happily on a dandelion on November 8, when the temperature was in the 60s. I’m sure the butterfly and dandelion are now gone. Some insects are able to seek shelter under eaves and other warm places and will come out again when the weather warms up.