Friday, June 17, 2011

Say Goodbye to Wormy Apples

Wouldn’t it be nice to go out to grandma’s apple tree and bite into a nice crisp juicy apple and not have to worry about worms? Just think of the work it would save when making apple sauce, cider, or pie. Say goodbye to wormy apples! It is a bit of work; it takes planning and careful timing. However, we can achieve worm free apples--without using pesticides-- if we know when to begin.

The nasty worms that inhabit and foul our apples all have a similar life cycle. The stage that bothers us the most, when they chew through our fruit, is their larval stage, the first stage after hatching from eggs. These eggs are laid right after our trees blossom in the spring. The larva that will soon be looking for a spot to spend the winter and turn into flies and moths come autumn. After the apples fall to the ground, depending on exactly which species of pest we are talking about, they spin cocoons or turn into pupas to wait out the winter months. Once spring is upon us, they burst from their hibernation and take to the air, ready to mate and lay eggs on our apple blooms.

The first step to ensuring worm free apples next year, is to get those wormy apples off the ground right now. If necessary, trees can be pruned, just enough so that you can get under them to clean up all the plant litter. Pruning back all branches that touch the ground is a good job for when the tree is completely dormant. Besides easing the job of cleaning up under the tree, it reduces the path ways that pests and disease follow to infect your fruit.

Once you can get under the tree to work, the leaf, fruit, and twig litter should be completely raked up. It can be fed to poultry or other animals, burned, or buried under at least three feet of dirt. Simply composting infested apples and other tree litter allows the worms to complete their life cycle and attack your fruit for another season.

Cleaning up under your apple trees before our rains set in has other benefits. It also helps prevent the tree from developing dry rot and fungus infections. These disease organisms often get their start in the duff and litter beneath trees. Once our weather begins to dry out in the spring, you will want to add a layer of compost or manure and some mulch beneath the trees drip line. This will help with water conservation, it reduces competition from weeds, and it supports the health of our all important soil organisms. Be sure to keep the organic matter at least a few inches away from the trunk to prevent disease organisms from gaining access to the bark and wood. The organic matter will provide nutrition for your trees as it breaks down. Just don’t forget to rake it up and move whatever is left next fall.

If you still have apples on your trees right now, you may want to take another step, after cleaning up the litter. Consider placing tarps under the trees, at least until all the apples fall. Some apple fruit pests burrow into the soil soon after the infected apples hit the ground. If you can block them from burrowing you will be ahead of the game next spring. (Remove the tarp after all the leaves and fruit fall, so the soil and roots can breathe.) Other apple worms climb up onto the trees trunk and hide in the bark. We can take care of these pests with Neem. Neem is natural oil from a tropical tree that is used by many organic gardeners for pest control. It is harmful to many insects, including those that are our friends, so it should be used carefully and in moderation. Certified organic farmers should contact their certifying organization to see if Neem is allowed. If not the organizations can make recommendations on other oils to use. Many horticultural oils, even those allowed by organic standards, can cause a build-up of heavy metals and other toxins in our soils and plants. Neem seems to be the safest, but it is not always allowed.

Neem oil is available from many nurseries, garden catalogs, organic farm suppliers, and natural food stores. Read the label carefully and ask any knowledgeable staff person for help if the label isn’t clear. The packaging should give directions, including dilution rates. (If you have more than one tree, or if your tree is very large, you may need something more than just a spray bottle to do the job.) Once you are ready to go, a dry still day when the bees are not busy is ideal. Consider spraying up to three times. First, after all your fruit is picked and before the rain has started; a second time in December or January, after the tree is fully dormant; and lastly, after the petals have all fallen from the tree and the bees are busy elsewhere. Thoroughly spray the bark and branches, and lightly spray the ground under the tree. Neem will not burn your plants leaves in spring, so go ahead and spray the young leaves too. Neem not only controls insect infestation it also reduces fungal infections, which is a great benefit in very wet winters. If you happen to live far away from anyone else who has apple worms treating your trees one year might be enough. However, the adult insects can fly in from several miles around, so most of us will need to spray every few years at least

If your apple trees are too big, too over grown, and too productive to undertake all this work, ask yourself if you really need trees that big. There are many very good varieties of dwarf apples available. If you are not overly attached to your old trees, you ought to consider replanting. You can keep the old trees for a few years, until the new ones get established. If you time it right, you can take out the old trees before the new ones bloom, so they just don’t hand their pest problems over to their replacements. However, the main advantage to planting new dwarfs is that their smaller size makes them easier to care for. They are just as susceptible to infestation as their larger relatives. If you do take out old trees, don’t let the apple wood go to waste. Let it age a few years and put it to good work on your BBQ or in your smokehouse. Apple wood gives food a nice, sweet, smoky flavor.

A great source of information on pruning and natural pest control can be found in the book Maintaining Your Edible Landscape Naturally by Robert Kourik. It is available by request from many libraries and used book stores.

Sources: If you are unable to find dwarf apple trees in the varieties you would like check out Burgess at or call (309) 662-7761 to request a free catalog. Last but not least, if you can’t find Neem oil locally or through your favorite catalog, Territorial seed company has it listed in their winter 2007 catalog along with some spray equipment, garden tools including a pruner for branches up to ¾ inch, and a sharpener for your pruning equipment. (800) 626-0866.


Published in the Hoopa People Paper, October 2007, Copyright Harvest McCampbell, all rights reserved.  Republishing by permission only.


Added a photo on 11.4.16. Text and photos copyright Harvest McCampbell.  Please feel free to share using the buttons below.  All other rights reserved.