Backyard Orchard Management: Harvest of Apples and Pears
Curtis E. Swift, Ph.D., Colorado State University Extension
Knowing when to harvest apples and pears has always been a problem for the backyard growers. Commercial growers determine when to harvest based on firmness of the fruit, ease of separation from the trees, ground color, and days from full bloom.
Fruit firmness is determined by using a penetrometer (fruit pressure tester) that records the pounds of pressure necessary for the plunger to penetrate the flesh. This is of value, especially in determining when apples are too soft or ripe for storage, rather than when picking should begin. When you purchase one of these gauges , information is provided on its limitations and use.
When an apple or pear is ready to pick, it usually can be separated from the spur without breaking the stem. To separate the stem from the spur, lift it with a slight rotating movement. In some cases Delicious apples will loosen and fall before maturity. Others such as Jonathan and Winesap may retain their fruit until they are overripe. In other words, ease of separation of fruit from the spur is not necessarily an indication of maturity. If, however, good apples and pears (not wormy) are dropping and other fruits can be separated easily, it is time to pick.
The red or overcolor develops according to genetics of the fruit, light intensity, nutrition and temperature. The latter three vary from year to year, making this key to maturity unreliable. "Ground color" (undercolor), however, can be used in some cases as an index to maturity. Ground color changes from leaf green to a lighter shade and eventually to a yellowish color when reaching maturity. The time to pick is usually when the first signs of yellow "ground color" appear.
Red apple sports that become red all over before maturity leave no ground cover visible. These sports, however, do not differ much in maturity from parent varieties. Consequently, the ground cover of the parent, (if present in the orchard), can be used as an indication of harvest time.
Jonathan and Cortland often drop excessively before ground color changes. The length of time from bloom to harvest is a better indication for these fruits. In fact, the latter, (days from full bloom), may be the best way to determine when to harvest. This is easier for the backyard grower and a lot less costly than buying a pressure guage and easier than trying to figure out ground color. The following chart gives approximate dates from full bloom to harvest. Full bloom is considered the time when 80% of the blossoms are open on the north side of the tree.
Days from full
Days from full
|Yellow Transparent||  70-100||Giffard||100-120|
|James Grieve||110-130||Dr. J Guyot||105-125|
|Cox's Orange Pippin||130-160||Eldorado||140-160|
|Rhode Island Greening||130-155||Anjou||140-165|
|Ralls||- --||Packham's Triumph||150-165|
|Golden Delicious||140-160||Flemish Beauty||160-180|
|Delicious (all strains)||140-160||Conference||160-180|
|York Imperial||155-175||Glou Morceau||170-200|
Placed on the Internet on January 28, 2003
Updated on August 8, 2009