Late summer and fall herald it's time for apple harvesting. Apples are a delicious, fun part of autumn so let's focus on how to harvest and store this great fruit.
When to harvest
Different apple cultivars will generally ripen at different times ranging between June for early varieties and September for late varieties. However weather conditions during the growing season will affect how fruit ripen. The best advise is to base your harvesting on whether the apples are mature rather than strictly on a calendar date. I always use the taste test.
There are several indicators of apple maturity. Mature apples are firm, crisp, juicy, well-colored and have developed the characteristic flavor of the cultivar. Color alone is not a reliable indicator of maturity. Red Delicious apples, for example, often turn red before the fruit are mature. Fruit harvested too early are astringent, sour, starchy and poorly flavored. Apples harvested too late are soft and mushy.
When harvesting apples, pick and handle the fruit carefully to prevent unnecessary damage. Sort through the apples during harvest. Remove and promptly use bruised or cut apples. Discard apples that are seriously damaged or show signs of decay.
How to store
The storage life of apples is largely dependent on the temperature and relative humidity during storage. Optimum storage conditions for apples are a temperature near 32 degrees Fahrenheit and a relative humidity between 90 and 95 percent. Apples stored at 32 F will keep two to three times longer than those stored at 45 to 50 degrees Fahrenheit. If the humidity during storage is low, apples will dehydrate and shrivel. When stored under optimum conditions, apples can keep for to three to five months.
Small quantities of apples may be placed in perforated plastic bags and stored in the refrigerator. Perforated plastic bags maintain a high relative humidity, while they prevent the accumulation of excess moisture inside the bags.
Large quantities of apples can be stored in a second refrigerator, cellar, unheated outbuilding or garage. Place the apples in perforated plastic bags or plastic-lined boxes/crates. Apples should be moved from unheated outbuildings and garages prior to extremely cold weather as storage temperatures will likely drop well below freezing. Apples will freeze when temperatures drop below 30 F. Frozen apples deteriorate rapidly once thawed.
Black spots and blotches
Apples may develop sooty blotch and flyspeck, two different fungal diseases that often occur together. Sooty blotch appears as dark brown to black, ½ inch or larger smudges on the surface of the apple. Flyspeck produces clusters of shiny, round, black dots. Individual dots are about the size of a pinhead. Environmental conditions that favor disease development are moderate temperatures and an extended wet period in late summer/early fall.
Sooty blotch and flyspeck live on the surface of the fruit. Damage is mainly cosmetic. The apples are still safe to eat. They’re just not very attractive. Cultural practices and fungicides can help control sooty blotch and flyspeck. Proper pruning of apples trees and fruit thinning promote drying and help reduce disease severity. Fungicides also may be necessary. If control measures fail, sooty blotch and flyspeck can be removed with vigorous rubbing.
Click here for OSU Home Orchard Apple and Pear Management Guide