PLANT & FRUIT
Barbara Baer & David Silverstein
WINTER CHILL HOURS
Winter Chilling is not necessary for most pomegranates. Chill hours are the
number of hours in the winter below 45 degrees (F). Some nurseries list 100-150
hours for chill hours for pomegranates but most pomegranates do not need any
chill hours. Some of the more cold-hardy varieties are an exception and do need a
little winter chilling for good fruit production. Many pomegranates are grown in
semi-tropical areas that get no temperatures below freezing in the wintertime; such
as the west central part of India where there are large plantations of pomegranates.
There are also several varieties that do not loose their leaves in the wintertime and
are considered evergreens. But these varieties cannot be grown in areas that have
any significant freezing weather. As to high temperatures, there are no areas in the
continental United States that are too hot for pomegranates. Pomegranates are even
being grown in Hawaii where they are reportedly are doing well.
This does not mean that pomegranates do not need a rest period, they do if
you want good fruiting. In west central India where the temperatures are not low
enough to really make the plants go dormant, to cause dormancy the Indian
farmers in the area have two methods. First, they do not water the shrubs and let
them dry out, this forces the plants into a type of natural drought protection causing
a rest period. If they have any rains in this period they pull the leaves off the plants
which will also cause a rest period. They have even figured out that by removing
leaves at different times of the year they can have fruit coming off year around.
The brief rest period is followed by flowering and fruit set.