In the ecosystem we live in different organism rely on other organism for survival. Furthermore, insects like lacewings and ladybird beetles prey on the pests that prey on our fruit trees. In order for us not to experience the heartache of losing a fruit, we can use a multitude of organic fruit tree pest management methods. This will not only keep our tree healthy, but will also not damage the environment. However, the key is to use a combination of these methods since doing only one will not be enough to protect your tree from damage. Although we will cover spraying in another article, we do not recommend using chemical pesticides. In fact, pesticides can kill the beneficial insects that feed on the pests.
1. Know the Common Diseases and Pests
Firstly, if you know which insects and diseases are more prevalent in your area, then you will be better prepared to protect your trees from damage. For example, fireblight may be more common in certain areas depending on the climate. In order to get this information, you can connect to the closest university cooperative extension or another local grower. Additionally it is important to know which fruit tree type is susceptible to which pest/disease. Here is a list of the most common pest/disease and its host provided by the University of California with links for more information.
|Codling Moth||Apple, pear, sometimes walnut, plum|
|Peach Twig Borer (PTB)||Peach & nectarine, almond, apricot, plum & prune|
|Brown Rot Fungus||Peach & nectarine, cherry, plum & prune, almond|
|Fireblight||Pear, apple, quince|
|Bacterial Canker||Peach & nectarine, cherry, plum & prune, pear (blast)|
|Peach Leaf Curl||Peach & nectarine|
2. Choose Disease Resistant Varieties and Rootstocks
Once you know the common diseases in your area, you can then choose the varieties that have resistance to that specific disease. For example Liberty apple trees are resistant to apple scab, fire blight, and cedar apple rust. However, different varieties have different levels of resistance. Even though you may grow a scab resistant apple tree, this may not fully decrease the chance of the tree getting scab. Additionally the rootstock also plays a role in disease resistance. For example, the Geneva series has rootstocks resistant to fireblight as well as crown rot. However, a fireblight resistant rootstock will only protect the root system from fireblight and not the whole tree.
3. Ensure Healthy Environment
If you plant in healthy soil (with good drainage, proper pH, with adequate water) and in full sun, then the tree will be stronger and better able to tolerate pests and diseases. However if these conditions aren’t there, then the tree will be weaker and less able to recover from injury.
4. Inspect Regularly
It is a good idea to inspect your tree regularly so that when you catch signs of a disease or pest, you can take immediate action and prevent further damage.
If you prune regularly during the early spring, then you will take away branches that rub against one another and make it less likely for damage and infection to happen. Additionally, keeping an optimal tree structure will allow more light and air to penetrate and therefore you will have a healthier tree. However make sure that your pruning equipment has been sanitized so that the cuts don’t promote infection and disease.
6. Guard Your Tree from Ring-barking Eating Rodents
If you use a tree guard to protect the tree’s bark, this will prevent rodents such as hungry rabbits and mice from eating around the bark. When they manage to eat all the way around the trunk, the tree can no longer transport carbohydrates to the roots which can kill the tree. There are different types of tree guards, such as plastic and wire mesh. However, we prefer using wire mesh since it allows air to flow without keeping the bark damp like other plastic guards. Therefore make sure there are no gaps between the mesh and the soil. You can also use a cane to keep the mesh upright.
7. Encourage Pest Predators
Birds and other animals, such as lacewings, lady beetles and hoverflies, can be natural pest controllers if you encourage them to stay close to your trees. If you provide winter food and some water for birds, they will eat the bugs in your trees and in your soil. As for the other pest-controllers, you can attract them with perennial flowers such as bugle, asters, daisies, and lavender. In order to keep these predators close, you can even create a bug hotel.
8. Remove Fallen Leaves and Fruit
It’s important to rake up the fallen leaves around the tree so that pests, such as apple blossom weevil, don’t overwinter. Additionally, if you rake around the tree then the pupae of bugs such as sawfly will be exposed to either birds or the frost. You can compost these leaves away from the trees. Also be sure to collect any fallen fruits.
9. Winter Wash Fruit Trees
Usually aphids, which feed on new shoots of fruit trees, won’t cause major problems especially on larger trees. However in severe cases and on younger trees, they may affect fruiting and cause distortion in the leaves. In order to get rid of them, you can wash the tree with a jet of water so that the eggs fall off. Another option is to apply a winter wash based on plant or fish oils in the early winter when the leaves drop and also in the spring before the trees start growing. Moreover, this winter wash can also take care of other overwintering pests.
Other Helpful Resources
There are many research institutions which offer great resources on organic fruit tree pest management methods. Here are some great ones.
- Cornell Cooperative Extension: Integrated Pest Management Guidelines
- WSU: Backyard Fruit Trees
- Penn State Extension: Fruit Production for the Home Grower
- University of Illinois Extension: Small Fruit Crops for the Backyard