Protecting Apples from Codling Moths using Bags

24 April 2015, written by Barbara Pleasant

One of the things I enjoy most about contributing to GrowVeg is the way problem-solving ideas get shared between continents. Today's topic is an excellent example. In the last few years, more and more American gardeners have begun bagging their most perfect apples to protect them from codling moths and other pests until they are ready to pick in the fall. It's an easy idea ripe for sharing!

I began experimenting with bagging apples a few years ago, after reading a study from the University of Minnesota in which home gardeners were able to grow more perfect apples by enclosing them in slightly modified plastic sandwich bags. Codling moth damage was cut to zero, and the bagged fruit showed excellent colour and flavour. I tried it, and it worked for me, too.

Left hand apples were bagged against codling moth; right-hand apples were not bagged

In the photo above, the nicely coloured apples on the left were grown in plastic bags.

Before getting into specifics, note that several non-plastic materials also can be used, for instance pantyhose footies. For maximum effectiveness preventing codling moth and scab, the footies are swirled in a mixture of water and kaolin clay before they are slipped over the thinned fruits. Bags made of paper, netting or other materials are less effective (and more unsightly) compared to plastic bags or hosiery sleeves.

Thin Apples First, Then Bag

Bagging apples is slow work, so your efforts should be concentrated on preserving the most promising immature fruits you can reach. Using sharp clippers or scissors, thin fruits by clipping off all but the largest, most perfect fruits in the cluster, as shown in the before-and-after photos here. You can bag apples as you thin them, or do it in two separate operations. For best results, bag apples before they grow larger than your thumbnail.

You can use either zip-closure or fold-top plastic sandwich bags. To modify them for bagging apples, snip off the two bottom corners with scissors, which allows moisture to drain away. Also trim off the top edge of zip bags, just above the zipper, which prevents unnecessary friction on the branch. Place the bags over the fruits, and secure them loosely with a staple from an ordinary office stapler. Be as gentle as possible, because rough handling can cause fruit to drop.

Bagging Fruits for Organic Growing

Once the bags are installed, there is nothing else to be done until the apples begin to ripen, because bagging eliminates the need to spray both fungicides and insecticides. When properly bagged, you can expect at least 80 per cent of the bagged fruit to be large and blemish-free, with only slight imperfections in the rest.

Bags for protecting apples from codling moths

Not surprisingly, various types of bags are now being used to protect other types of fruits, from bagging date palms in Egypt, guava in Pakistan, or mangoes grown in India and China. In the US, gardeners in Wisconsin have been tying paper bags around bunches of grapes for decades. When it comes to worthwhile organic techniques, bagging apples is a great one to try.

By Barbara Pleasant