Green Industry Resources
Hort Update- Seasonal Information for the Green Industry
Harvesting and Storing Apples
Harvesting apples at the proper stage of development is the first step toward ensuring high quality garden produce that tastes great and stores well. If picked prematurely, apples are likely to be sour, tough, small and poorly colored; if picked overripe, they may develop internal breakdown and store poorly.
To harvest apples correctly, you must be familiar with the term "ground color." Ground color is the color of an apple's skin, disregarding any areas that have become red. In red-fruited cultivars, observe the portion of the apple that faces the interior of the tree. When the ground color of red cultivars changes from leaf green to yellowish green or creamy, the apples are ready to harvest. In yellow cultivars, the ground color becomes golden. Mature apples with a yellowish-green background color are suitable for storage.
Most apple cultivars have brown seeds when ready for harvest. However, seeds may become brown several weeks before proper picking maturity, so seed color should not be used as the sole method of evaluating maturity.
Early maturing apples, those that reach maturity in August and early September, are sometimes called ‘summer apples’. Early maturing varieties such as Honeycrisp, Paula Red, Gala, and Jonagold that will be eaten immediately may be ripened on the tree.
Apples that are to be stored should be picked when mature, but hard: i.e., showing the mature skin color but with a hard flesh. When harvesting, do not remove the stems from storage apples as this wound will create an opening for rot fungi. Be sure to store only apples without bruises, insect or disease damage, cracks, splits, or mechanical injury. Any damaged fruits should be used for fresh eating, or processed.
Many cultivars of apples store moderately well under home storage conditions for up to six months. Late maturing varieties are best suited to long-term storage. These apples can be stored in baskets or boxes lined with plastic or foil to help retain moisture. Varieties that tend to shrivel can be stored in in plastic bags that have several holes for gas exchange.
Always sort apples carefully and avoid bruising them. The saying 'one bad apple spoils the barrel' is true because apples give off ethylene gas which speeds ripening. When damaged, ethylene is given off more rapidly and will hasten the ripening of other apples in the container.
Because of their sugar content, apples can be stored at 30-32°F without freezing the tissue. In general, apples ripen about four times as fast at 50°F as at 32°F, so they should be kept as close to 32°F as possible for long-term storage. When stored at this temperature, apples may last for up to 6 months.
Apples often pass their odor or flavor to more delicately flavored produce and the ethylene given off by apples can accelerate ripening in other crops. When possible, store apples away from other fruits and vegetables.
Harvesting and Storing Pears
Knowing when to harvest pears is confusing to many gardeners, because tree ripened pears often do not usually have good quality. They develop stone or grit cells, or a mealy texture that makes the fruit less desirable. Pears ripen from the inside out, a characteristic more pronounced in tree ripened fruits. So when the outside flesh has become slightly soft and appears to have good eating quality, the inside flesh is soft and brown.
Tree ripened fruits have shorter shelf and storage life, which may be particularly true this year with summer's continued high temperatures. Fruits left on the tree too long will go quickly from slightly under-ripe to rotting.
For good flavor and texture, pears must be ripened after harvest. Completing the ripening process indoors reduces the development of stone cells and evens the ripening of interior and exterior flesh.
When to Harvest
Harvest pears while they are still quite firm (hard) but the skin color, or ‘ground color’, has lightened to a pale green or greenish-yellow color. Ground color is the color of a pear's skin, disregarding any areas that have become red. Don’t allow pears to become fully yellow on the tree before harvesting. Additional indications that pears are ready to harvest are when the fruit stem easily separates from the branch with an upward twist of the fruit and when the lenticels (spots on fruit surface), which are white or green on immature fruits, become brown.
Most pear cultivars can be easily removed from the tree when they are ready to harvest. Grasp a fruit, and tilt it to a horizontal or upward position to detach its stem from the tree. 'Bosc' pears, however, usually need to be clipped from the tree with pruners, even when they have reached maturity.
After harvest, pears should be held at 60 to 65°F for 1 to 3 weeks, depending on the type of pear. During this time the pears will ripen and soften. High temperatures (75°F and higher) after picking will cause the fruit to break down without ripening. After ripening, pears should be canned or preserved.
To keep pears longer in storage, do not allow them to ripen after harvest. Sort the immature pears for defects, discarding any with bruises, mechanical damage or insect damage, then place them into cold storage at 29-31°F and 90% humidity. Perforated plastic bags or partially sealed plastic containers can be used to store small groups of fruit while maintaining high humidity but allowing gas exchange of ethylene, which hastens ripening. Store pears away from apples, onions, potatoes or any other ethylene-producing fruits or vegetables.
Regularly inspect stored fruits for mold, and fruit breakdown. Pears in a good storage environment should last 2-4 months.
Ripen small amounts as needed, by moving them to a warmer location, 60-65°F, for a few days.