I have bought an orchard which has 42 apple trees 30 apricots and 22 walnuts. And I want to know if my orchard is suitable for apple farming or not. I have red that apple trees should be in a location that at least goes under 7°C at least 1000 hours in a year.

In this website I can see how whether was in my orchards area. https://www.accuweather.com/en/ir/avenliq/528913/month/528913?monyr=1/01/2019

How can I calculate how many hours my orchard has been under 7°C.

  • I can't answer that directly, but I think where you are is colder than West Azerbaijan (depending on proximity to the Caspian sea), and West Azerbaijan is one of the areas where apples are cultivated, see here scirp.org/journal/PaperInformation.aspx?PaperID=77810
    – Bamboo
    Commented Mar 28, 2019 at 21:53
  • Thank you for your answer we are in east Azerbaijan of Iran. My garden is in 1332 altitude in "Avenliq village". Here people say apples of higher altitude Villages like "ishlaq village" Have better quality. they altitude is about 1600. I don't even know what they mean by quality. Commented Mar 28, 2019 at 22:14
  • They probably mean a better flavour... the greater altitude will mean cooler temperatures in winter. I checked your profile, so I knew you were in East Azerbaijan...certain varieties of apples are grown in Iran, but in the colder regions. Your link requires me to accept cookies and ads, which I''m not prepared to do, so I was unable to look at it.
    – Bamboo
    Commented Mar 28, 2019 at 23:09
  • Better "quality" apples may depend on may things, but the basic point is that apple trees will not flower (and therefore will not produce any fruit at all!) unless they become dormant in winter, and that requires a period of low temperatures. But since the OP's orchard already has 42 apple trees, it would be very strange if those trees were not already producing fruit - unless the previous owner has intentionally deceived the OP about what he has just bought!
    – alephzero
    Commented Mar 29, 2019 at 13:03
  • @alephzero Thanks for your answer. I researched more and there is no problem about flowering. these apples are about 10 years old and well established. And about low quality apples they say in Turkish "pukalir" which means apple pulp is not as hard or dense like those of higher altitudes. And another term villagers used was "pishir" which means they get cooked in Hot summer. I don't understand these terms and I just translated it. Farming in these places is so much traditional for example they don't even now what mulching is. So I think maybe these problems are solvable. Commented Mar 29, 2019 at 20:44

1 Answer 1


If you have a local weather station that records the daily temps, get their last several years records, and enter them into a spread sheet.

Threshold = 7
Sept    High   Low   Hours
1       15       6
2       20      11
3       10       2

If (Low >= threshold) hours = 0 Else hours = 24 * (Threshold - Low)/(High - Low)

For Sept 1 you have 24 * (7-6)/(15-6) = 2.something For Sept 2 it didn't get cold enough = 0 For Sept 3 you have 24 (7-2)/(10-2) = 15

This is an approximation that assumes that the high and the low are about 12 hours apart. Usually the low is about dawn, and the high in mid afternoon, so this under estimates chilling hours somewhat.

If you want degree days, then replace 24 by 1.

It's near enough for most purposes. Chilling requirements aren't that precisely known. And for most things, different amounts of chill have different effects. For some chilling only counts when it's between to values, say -2 and +6. When it's colder than that the 'clock' freezes.

Chilling also varies by cultivar for apples. Growing apples on the Canadian Prairies required breeding for higher chilling requirements to prevent late frosts from killing all the buds.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.