I have been trying to figure out the "chill hours" in my area. This seems to be a very inexact science with several different methods for calculating. Also I can't seem to find a source which has calculated this ( over several previous years)for my area. No one in the area ( incuding the extension service and the nurseries) seems to be able to help me. I get different advice from everyone and it is all conflicting . Pecan trees with about a 300 hour chill requirement grow and produce well here but many of the fruit trees in the nurseries which they claim will grow well here (but will they produce?) are 700-900 hours. I found a internet source which showed that the west Texas area requires 700 chill hours and that area is similar to my area in SE New Mexico. Does anyone have a source for determining chill hour range in a specific area. (specifically in Southeast New Mexico. If not ,does any one have advice from personal experience as to what type and / variety of fruit trees will grow and produce crops here. Thanks for any information
Chill hours in Southeast New Mexico
Strange that your extension service doesn't have that info - very frustrating.
Okay, here's what digital seed says about chill hours:
"Many fruit trees from temperate climates must have a certain amount of cold weather in order to fruit normally. This requirement which varies with the cultivar (and sometimes with the climate) is referred to as chill hours.
There is some disagreement over how to calculate chill hours. Some experts refer to the total number of hours experienced between 32 and 45 degrees F (during the dormancy period). Some offset the chill hours that occur in a 24-hour period by any hours in that same period when the temperature goes above 65 degrees F. And some give extra weight to early season chill hours (see Chill Hours Reconsidered for an interesting discussion about this issue). To complicate matters, many fruit tree suppliers neglect to mention which method is being used.'
The long way to figure out chill hours (I keep spelling it "hourse" - grr!) is to go to the NOAA site and look at the historic records for an actual count for a few winters. Or you could purchase a min/ max thermometer and chart it yourself, but it would take a couple of years to be able to average out your data.
The easy way? Ask your neighbors/ co-workers what works for them. Look at the fruit trees in your neighborhood - don't forget that micro-climates greatly affect temps - especially on slopes, I've found.
I'm kinda curious as to why you asked this on the soil and composting forum?
Regardless, hope I gave you somewhere to start, good luck! I was totally lost when I began gardening in the desert back in the last century, lol!