Bloom Dates for Red Delicous Apples

Program Contact: Tianna DuPont, Regional Specialist, Tree Fruit
(509) 663-8181 • tianna.dupont@wsu.edu

Full Bloom Dates for Red Delicious Apples

1922 to Present at the WSU Tree Fruit Research & Extension Center Wenatchee, WA

blomdateThe data in the table was provided from 1922 to 1993 by the various people who worked for the National Weather Service office in Wenatchee, for the fruit growers and public. Since the NWS office was closed in 1993, the date of full bloom has been monitored at the WSU Tree Fruit Research and Extension Center by the Regional Extension Specialist from the Chelan / Douglas County office of WSU Extension. These data are of both significant historical and practical importance, and are used by various individuals to better understand production, harvest and quality of the past crops produced in the region.

Full bloom is defined as the day that 60% of “king blossoms” are open on the north (shady) side of the tree. (The king blossom is the larger dominant blossom that is usually found in the center of the blossom cluster, surrounded by the yet unopened “side blossoms.”)  Frosted blossom buds may open with an incomplete or missing king flower.

The average date of Red Delicious apple full bloom at this site is April 27.

Red Delicious is a relatively late blossoming apple cultivar, and other apple cultivars on warmer sites in the local region will bloom up to a week earlier.  Elevation and slope aspect are quite variable over short distances in this region, and very influential in relation to blossom development rate.  Lower elevation orchards (~700 ft. elevation) may see blossoms up to a month before higher elevations (~3400 ft.) in this region.  Apricots bloom first in the region, usually three weeks before Red Delicious growing on similar sites.  Then peaches and nectarines bloom, about 14 – 17 before apples, then cherries about 10 – 14 days before apples, then pears about 7 – 10 days prior, then come the apples.

The date of full bloom at the WSU Tree Fruit Research and Extension Center is used as a relative comparison of one year to another.

Some Fun Facts:

The earliest Full Bloom date all time at this site was recorded in 2015.  April 9, 18  days ahead of normal.  This resulted in most tree fruit harvest dates that season to occur about 10-14 days earlier than normal.

As of 1925 through 2011, the 86 year average full bloom date in Wenatchee is: April 27 at 2:11 p.m.

The Average Full Bloom Date From 1995-2005 is: April 23 at 9:49 p.m.
The Average Full Bloom Date From 1990-1999 is: April 21 at 7:12 a.m.
1980-89: April 25 at 9:36 p.m.
1970-79: April 30 at noon.
1960-69: April 28 at 7:12 p.m.
1950-59: May 2 at 11:59 p.m..
1940-49: April 26 at 9:36 a.m.
1930-39: April 26 at 9:36 a.m.

Bloom by Year Bloom Date, Earliest to Latest
Year Month & Date Year Month & Date
1922 5/16 2015

1934

4/9

4/11

1923 5/8 2004 4/13
1924 4/30 1992 4/14
1925 5/1 1990 4/15
1926 4/28 1994 4/16
1927 5/1 1941 4/18
1928 4/28 1947 4/18
1929 5/2 1930 4/19
1930 4/19 1940 4/19
1931 4/27 1988 4/19
1932 4/28 2000 4/19
1933 5/1 1987 4/22
1934 4/11 1998 4/22
1935 5/1 2003 4/22
1936 4/27 2005 4/22
1937 5/8 1973 4/23
1938 4/28 1977 4/23
1939 4/24 1981 4/23
1940 4/19 2010 4/23
1941 4/18 1939 4/24
1942 4/24 1942 4/24
1943 4/28 1962 4/24
1944 4/29 1966 4/24
1945 5/1 1983 4/24
1946 4/28 1991 4/24
1947 4/18 1953 4/25
1948 5/12 1986 4/25
1949 4/27 1989 4/25
1950 5/10 1995 4/25
1951 4/28 2012 4/25
1952 4/27 1980 4/26
1953 4/25 1996 4/26
1954 5/6 2007 4/26
1955 5/14 1931 4/27
1956 5/1 1936 4/27
1957 4/30 1949 4/27
1958 4/30 1952 4/27
1959 4/29 1961 4/27
1960 4/29 1965 4/27
1961 4/27 1999 4/27
1962 4/24 2001 4/27
1963 5/1 1926 4/28
1964 4/30 1928 4/28
1965 4/27 1932 4/28
1966 4/24 1928 4/28
1967 5/4 1943 4/28
1968 4/28 1946 4/28
1969 5/4 1951 4/28
1970 5/1 1968 4/28
1971 5/5 1978 4/28
1972 5/5 1979 4/28
1973 4/23 2002 4/28
1974 5/1 2006 4/28
1975 5/9 1944 4/29
1976 5/2 1959 4/29
1977 4/23 1960 4/29
1978 4/28 1924 4/30
1979 4/28 1957 4/30
1980 4/26 1958 4/30
1981 4/23 1964 4/30
1982 5/5 1984 4/30
1983 4/24 1985 4/30
1984 4/30 1925 5/1
1985 4/30 1927 5/1
1986 4/25 1933 5/1
1987 4/22 1935 5/1
1988 4/19 1945 5/1
1989 4/25 1956 5/1
1990 4/15 1963 5/1
1991 4/24 1970 5/1
1992 4/14 1974 5/1
1993 5/7 2009 5/1
1994 4/16 1929 5/2
1995 4/25 1976 5/2
1996 4/26 1997 5/2
1997 5/2 1967 5/4
1998 4/22 1969 5/4
1999 4/27 2008 5/4
2000 4/19 1971 5/5
2001 4/27 1972 5/5
2002 4/28 1982 5/5
2003 4/22 1954 5/6
2004 4/13 1993 5/7
2005 4/22 2011 5/7
2006 4/28 1923 5/8
2007 4/26 1937 5/8
2008 5/4 1975 5/9
2009 5/1 1950 5/10
2010 4/23 1948 5/12
2011 5/7 1955 5/14
2012 4/25 1922 5/16

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