To all southeastern and southwestern pear growers, let’s try an experiment and see if we can come up with the minimum chilling requirement for pear varieties for which there is no good published chilling data. Here is how to help. Note which years your pear varieties did not bloom or bloomed in dribs and drabs. Use the chilling hour calculator available from your state agricultural collage to calculate the number of chilling hours the closest weather station to you reported. Then post that number with a brief description of what your pear tree actually did.
Here’s an example. During the year that I got around 400 chilling hours my Tennessee pear did not bloom at all. This past winter it got 525 hours and bloomed in dribs and drabs. It blooms well (explodes into flower) when I get 600 hours or more. Given this I’m saying the chilling requirement is around 550 hours.
For my climate I calculate the chilling hours between from between mid October and when the tree begins to break dormancy. That’s mid to late February here for most varieties.
Let’s work together and see if we can nail some of this down for our more regional varieties for which there is no published data.