Why Do People Hang Milk Jugs From Apple Trees?

Pests

• Apple trees are affected by several types of pests, including mites, scales, worms and moths. The codling moth is perhaps the most serious pest in apple production and is the most common pest targeted with milk jug pest treatments. The larval codling moth works its way inside of apples and feeds on the fruit from inside. The full grown larvae nestle under bark to undergo the pupal metamorphosis. The adult moths then lay eggs directly onto the apples and the larvae worm their way inside of the fruit to complete the cycle. If uncontrolled, a single codling moth and its larvae can destroy the fruit of an entire tree.

Milk Jug Concoctions

• The milk jugs that hang from apple trees contain a concoction intended to attract codling moths and other pests. When they enter the liquid concoction to feed, they become trapped inside the jug and eventually die. There are several different concoctions that apple growers use for this purpose, but they all basically consist of a mixture of sugar or molasses and water. One cup of sugar or molasses is added to 1 quart of water and then mixed until the sweetener dissolves. The jug may be filled with more water, if desired. Other common ingredients added to the mixture include 1 cup of apple cider vinegar, yeast and a chopped banana peel.

Placement

• The jugs should be hung from sturdy branches on the apple tree to support the weight of the jug. Water-filled milk jugs are sometimes anchored on the ground to force lateral branches downward, so this is a perfect opportunity to achieve dual results. Forcing the lateral branches down encourages the branches to spread out and receive maximum sunlight. Take the cap off the milk jug and hang it with a soft twine. For better results, several milk jugs can be hung in different places throughout the tree. Try using several 1/2-gallon milk jugs in place of a single gallon-sized jug.

Maintenance

• Check the jug every few weeks to see how many pests are trapped. More water will need to be added periodically as the water evaporates. If the jug appears to be filled with pests, dump the bugs and sweet concoction, clean the jug and fill it with a fresh attractant mixture. It is also helpful to check the branches where the twine is tied. If the twine appears to be cutting into the tree, wrap the twine around a second branch to distribute the weight. Another option is to place a piece of cloth, such as an old handkerchief, under the twine to serve as a cushion.