Apple trees (Malus spp.) are prized by home gardeners for their fresh fruit and fragrant blossoms. Depending on the species of apple tree, hardiness varies, but many are hardy in U.S. Department of Agriculture plant hardiness zones 3 through 8. Pests and disease can be a serious nuisance for apple growers. Bagging your apples early in the growing season is an effective way of preventing problems.
Bagging apples involves putting a cloth bag over apples while they’re ripening to protect them from disease and pests. The process originated with the Japanese, who use specially designed cloth bags. According to the University of Kentucky, studies conducted between 1995 and 1998 on the effectiveness of bagging apples showed that the bags are effective in protecting the fruit from insects such as coddling moths and stinkbugs, and also from diseases such as cork spot and sooty blotch.
Types of Bags
The Japanese process of bagging apples used cloth bags with a slit near the opening. These bags also had a wire woven into the top of the bag along one side. In the United States, cloth bags are available at garden centers, but paper bags are just as effective as cloth. For example, a 3-pound paper bag can be used. If you cut the bag down to 6 inches long and cut a 1 1/2-inch slit into the opening, you will have a bag that is almost equivalent in size to the Japanese bags.
Thinning the fruit before or at the time of bagging is done to ensure larger and healthier fruit and to encourage blooms in the following growing season. According to The Home Orchard Society, the earlier you thin the fruit, the larger it tends to be as a result. Typically the fruit is thinned when it is about 1/2 to 3/4 inch in diameter, removing all but one fruit per cluster, or leaving one fruit for every 6 to 7 inches of limb.
Bagging the Apples
If you use the Japanese cloth bags, the process of bagging is simple. Place the bag over the fruit and insert the stem into the slit. Gather the top in a pleated fashion and use the wire to secure the bag at the branch. When using a paper bag to bag your apples, slide the apple inside the bag so that the stem is inserted into the 1-1/2 inch slit and the top of the bag slides over the supporting branch. Close the top of the bag and secure it with a twist tie or thin piece of plastic-coated wire.
Some gardeners prefer to thin and bag the fruit at the same time, while others thin during flowering and bag later. Generally, fruit can be thinned and bagged in the spring when the fruit reaches about 3/4 inch in diameter. This is typically about three weeks after petal fall. The bags remain on the fruit until about three weeks before the apples are ready to harvest. Bags are removed at this point to allow the sun to reach the fruit to ensure good color. Once the bags are on the fruit, no insecticide or fungicide sprays are needed.